FINAL REPORT
 
SOUTH CAROLINA EAST COAST GREENWAY-
TRANSPORTATION SAFETY, ROUTE LOCATION
AND FACILITY NEEDS STUDY
 
Prepared for
South Carolina State University
James E. Clyburn University Transportation Center

 

Prepared by
Wayne A. Sarasua, PI
David B. Clarke, Co-PI
William J. Davis, Co-PI
 
 
Project Funded by
U.S. Department of Transportation
Research and Special Programs Administration
 
 
August 2004




Executive Summary

The East Coast Greenway (ECG) is a multi-modal transportation corridor currently being developed for bicyclists, hikers and other non-motorized users, extending from Calais, Maine to Key West, Florida. Further information regarding this facility is available on the East Coast Greenway Alliance’s website at www.greenway.org. A 259-mile length of the Greenway extending through coastal regions of South Carolina was evaluated by a study team, comprised of The Citadel, Clemson University and South Carolina State University, to assess route conditions and address other route planning issues within a seven-county coastal area.

An extensive Geographic Information System (GIS) database was assembled within the corridor to evaluate transportation issues, bicycle suitability, alternative route comparisons, facility needs assessment, route continuity and improvement recommendations. The total database consists of 137 sections and 450 segments, with the modified existing Greenway route, reflected in route maps and route tabulations, consisting of 72 sections and 234 segments. Various sections within the corridor require the Greenway to extend along existing roads and a primary concern occurs when non-motorized and motor vehicle traffic operate in close proximity, within a common right-of way. A Bicycle Compatibility Index (BCI) Level of Service (LOS) procedure developed by the Federal Highway Administration was used to evaluate geometric, traffic and landuse conditions along route segments. In addition, GIS coding of the route allowed a variety of useful tabulations describing existing conditions along the SC East Coast Greenway.

Study results and findings include the following:

  • 11 % (27.6 miles) of the ECG route currently exists along either a bike lane or multi-use path.
  • 20 % (50.1 miles) of the ECG route is located along roadways with paved shoulders.
  • 26 % (69.0 miles) of the ECG route is located along roads with a speed limit of 40 mph or less.
  • Based on BCI-LOS analysis, 41% (106.6 miles) of the ECG route segments fall within the desirable A through C designation, with BCI value ranging from 1.11 to 3.39.
  • Based on BCI-LOS analysis, 59% (152.9 miles) of the ECG route fall within the undesirable D through F designation, with corresponding BCI value ranging from 3.45 to greater than 7.73.
  • 13 route segments exhibiting the worst conditions along the greenway, based on BCI-LOS F with an index rating of 5.30 or greater. A summation of these segments produces a total of 18.7 miles, or 7% of the greenway length in SC. Ten segments are located along various sections of US 17.
  • 31% (80.7 miles) of the route exists along roadways experiencing heavy traffic volumes, greater than 10,000 vehicles per day, of that total, 4% (9.66 miles) are located on roads with extremely heavy traffic in excess of 40,000 vehicles per day.
  • 51 % (132.1 miles) of the ECG route exists along roadways with a speed limit of 55 or 60 mph.

Table of Contents

No. Section
  Executive Summary
I. Introduction and Study Overview
II. Literature Review
III. Data Collection
IV. Route Analysis Using BCI
V. Summary of Existing Greenway Route in SC
VI. Lowcountry Region - Route Analysis
VII. Charleston Region – Route Analysis
VIII. Wacammaw Region – Route Analysis
IX. Findings and Recommendations
  Acknowledgement
  References
  Appendix A – Summary of Bicycle Compatibility Index (BCI) procedure
  Appendix B – Database and BCI rating for SC ECG corridor segments

List of Tables

Table Contents
1 Overview of Project Tasks
2 BCI Value, LOS & Compatibility Ranges
3 Tabulation of Adjusted BCI Route Segments, N= 89
4 Route Tabulation of Bicycle Facilities
5 Route Tabulation of Sidewalks
6 Route Tabulation by Shoulder Type
7 Route Tabulation by Speed Limit
8 Route Tabulation by ADT volume
9 Route Tabulation by BCI/LOS Rating
10 Best Route Segments Along Greenway
11 Worst Route Segments Along Greenway

List of Figures

Figure Contents
1 SC East Coast Greenway Corridor Location Map
2 Overview of Data Collection and Analysis Process
3 East Coast Greenway Route Section Flow Chart
4 Average Daily Traffic versus Unadjusted BCI Rating, n = 450
5 Average Daily Traffic versus Adjusted BCI Rating, n = 450
6 SC East Coast Greenway, Overview Map I (Lowcountry)
7 SC East Coast Greenway, Overview Map II (Charleston)
8 SC East Coast Greenway, Overview Map III (Waccamaw)
9 SC East Coast Greenway, Map 1, Lowcountry (Savannah to Ridgeland)
10 Photo and route data for US 17 near GA State Line, Jasper County
11 Photo and route data for Old Charleston Hwy, Jasper County
12 Photo and route data for Old Kings Hwy, Jasper County
13 Photo and route data for US 17 near Combahee River, Colleton County
14 SC East Coast Greenway, Map 2, Lowcountry (Ridgeland to Yemassee)
15 SC East Coast Greenway, Map 3, Lowcountry (Yemassee to Jacksonboro)
16 SC East Coast Greenway, Map 4, Charleston (Jacksonboro to Johns Island)
17 Photo and route data for West Ashley Greenway, Charleston County
18 Photo and route data for US 17 at Ashley River Bridges, Charleston County
19 SC East Coast Greenway, Map 5, Charleston (Johns Island to Charleston)
20 Photo and route data for multi-use path on Lockwood Dr, Charleston County
21 Photo and route data for Murray Blvd, Charleston County
22 SC East Coast Greenway, Map 6, Charleston (Downtown Charleston)
23 SC East Coast Greenway, Map 7, Charleston (Mt. Pleasant)
24 Photo and route data for bike lane on Coleman Blvd, Charleston County
25 Photo and route data for multi-use path on Ben Sawyer Blvd, Charleston County
26 SC East Coast Greenway, Map 8, Charleston (Mt. Pleasant to Santee River)
27 SC East Coast Greenway, Map 9, Waccamaw (Santee River to Georgetown)
28 SC East Coast Greenway, Map 10, Waccamaw (Downtown Georgetown)
29 Photo and route data for Great Pee Dee/Waccamaw River Bridge, Georgetown County
30 Photo and route data for Kings River Rd, Georgetown County
31 SC East Coast Greenway, Map 11, Waccamaw (Georgetown to Litchfield Beach)
32 Photo and route data for multi-use path on Wilbrook Blvd, Georgetown County
33 Photo and route data for multi-use path on US 17, Georgetown County
34 SC East Coast Greenway, Map 12, Waccamaw (Litchfield Beach to Myrtle Beach)
35 Photo and route data for bike lane on US 17 Bus, Horry County
36 SC East Coast Greenway, Map 13, Waccamaw (Myrtle Beach)
37 Photo and route data for multi-use path on Grissom Pkwy, Horry County
38 Photo and route data for S. Ocean Blvd, Horry County
39 SC East Coast Greenway, Map 14, Waccamaw (Myrtle Beach to North Myrtle Beach)
40 Photo and route data for bike lane on Hillside St, Horry County
41 SC East Coast Greenway, Map 15, Waccamaw (North Myrtle Beach to NC Sate Line)
42 Cross Section Design Criteria for Multi-use Greenway Path

 

I. INTRODUCTION AND STUDY OVERVIEW

Plans for development of the East Coast Greenway (ECG) in South Carolina have been underway for the past decade. Initial efforts produced an overall corridor map, as shown in Figure 1. While this map identifies planned and completed facilities, along with general linkages between major destinations, specific details of future off-road path locations and interconnecting on-road segments were purposefully left for local and state government officials to address, within the context of their normal transportation planning efforts. Currently, studies are in progress with the aim of developing a master plan for proposed Greenway facilities structured within the framework of three coastal areas of South Carolina including; Lowcountry, Berkeley-Charleston-Dorchester and Waccamaw regional planning districts. Routes evaluated in this study were coordinated with on-going efforts in each district.


Figure 1 – SC East Coast Greenway Corridor Location Map

This study focuses on evaluation of the SC ECG, as it currently exists, and includes other readily apparent alternate routes within the corridor limits depicted in Figure 1. Since only small portions of the planned facilities are completed, most of the current route connections are situated along existing roads. In taking a multi-day trip along the Greenway today, as many cyclists are already beginning to do, most of the linkages would be made on existing roads. Once master plan studies are finalized, proposed off-road path facilities are likely to be built in stages, and traveling extended sections of the Greenway will continue to rely upon on-road connections for many years to come until future projects are funded, designed and constructed. The Bicycle Compatibility Index (BCI) Level of Service (LOS) procedure, developed by the Federal Highway Administration (FHWA) (1), was used as the basis for conducting route evaluations. Results of this study are intended to help planners and transportation officials gain a better understanding of the current Greenway status and tasks required to implement needed improvements within a systematic and time efficient manner. An overview of tasks conducted for this study is provided in Table 1.

Table 1 – Overview of Project Tasks
Overview of Project Tasks
1. Coordinate with city planners, regional planners, advocacy organizations and other stakeholder groups in three regional planning areas – Task involved obtaining documents, maps and information describing plans related to current location and status of greenway improvements
 2. Collect data along perspective routes within East Coast Greenway corridor – Task involved driving routes within the corridor, collecting field data and obtaining SC DOT/local roadway data pertaining to volume, speed, width and classification. Specific data collection tasks included:
  • Inventory existing and planned bike/ped. facilities along corridor
  • Identify significant points of interest along corridor
  • Inventory traffic volumes, travel speeds, lane widths, shoulders and other pertinent information along proposed routes and potential alternate (or interim) parallel routes
  • Identify problem areas along corridor
  • Identify other possible bike/ped. network connections along corridor
3. Analyze and Evaluate Corridor Data – Work conducted for this task will focused on evaluating data and route characteristics through the following steps:
  • Apply Federal Highway Administration Bike Suitability Criteria to rate roadways
  • Determine anticipated route designations and Level of Service
  • Prioritize corridor improvement needs and identify problem locations
  • Assemble comprehensive plan for corridor to address existing route configuration
4. Prepared Draft Report and Preliminary Route Maps – The objectives of this task are to aggregate and summarize important route characteristics in a manner for soliciting feedback from project stakeholders and interested parties.
5.  Solicit feedback, comments and concerns from stakeholders – Through distribution of the draft report and preliminary route maps, a wide variety of public input is to be obtained. This is important, because ownership of the various greenway segments will occur at the level of local government and opportunities to provide input are crucial to gaining support for final project concepts. Steps for this task include:
  • Tabulate feedback and address stakeholder concerns
  • Update report and route maps
6.  Finalize Report and Submit Copies to Major Stakeholders – Input obtained from stakeholder representatives is to be incorporated into final report and distributed widely to government agencies and other interested parties. Project tasks will be conducted in collaboration with a Project Advisory Committee consisting of state and local agency representatives. A partial list of members includes the following individuals:
  • James Gardner, Jasper Co. Parks & Rec., SC Chair, East Coast Greenway Committee
  • Tom Dodds, Bicycle Coordinator, SC Dept. of Transportation
  • Hiala Maze, Planner, Berkeley-Charleston-Dorchester Council of Governments
  • Janine Peccini, Planner, Waccamaw Regional Planning & Development Council
  • Keri McAllister, Planner, Lowcountry Council of Governments
  • Linda Ketron, Chair, Bike the Neck
  • Jack Walker, Sr. Planner, City of Myrtle Beach
  • Joyce Rowley, Sr. Planner, City of North Myrtle Beach

II. LITERATURE REVIEW

Evaluation of bicycling conditions and level of service has been addressed from two fundamentally different approaches over the past decade. The first approach is based on determination of capacity and LOS for bicycle facilities, multi-use paths and bike lanes predicated primarily on flow parameters. This approach is useful in determining how many cyclists, pedestrians and other path, or lane, users can be accommodated by a facility of a specified width. Methods for these type procedures were developed by Botma (2), Allen e.t.a.l (3) and others. The results of which are compiled in Chapters 11, 18 and 19 of the Highway Capacity Manual (4.) The second approach is focused on evaluating the compatibility or suitability of bicycle travel along existing roads based on roadway conditions and traffic operation factors. This approach was deemed most applicable to evaluate the East Coast Greenway in South Carolina, and a number of studies centered on this approach are cited in the following paragraphs.

Sorton and Walsh (5) evaluated stress level for casual and experienced cyclists based on curb lane width, adjacent traffic volume, and adjacent traffic speed. Davis (6) used route data to compare various combinations of conditions affecting cyclist perception of exposure to traffic volume, traffic speed, lane width, grade, pavement condition and several other factors. Additional work on this aspect of cycling includes Landis (7) and Kahn (8.) Putman and Ross (9) used suitability analysis methods to evaluate 700 roadway segments in Madison, Wisconsin. The results demonstrated the application of suitability methods for use on a network basis.

200 participants evaluated video-recorded conditions for roadway locations in different cities and provided a value indicating their comfort level based on work by Hughes and Harkey (10) and Harkey et al., (11,12,13.) Physical measurements at each site were used in a regression analysis to determine a bicycle compatibility index. Factors used in the prediction formula included curb lane width, presence of bike lane, exposure to parking, motor vehicle speed, lane volumes, and type of developed area. This work provided the basis of The Bicycle Compatibility Index: A Level-of-Service Concept, Implementation Manual, FHWA-RD-98-095, (1.) This method was used to conduct route analysis along the 259-mile length of East Coast Greenway in coastal South Carolina. The BCI index was developed for urban and suburban roadway segments, however, no such method has been developed for similar rural roadway segments. Thus, the BCI analysis procedure was adapted for comparative evaluation of rural roadway segments.

Since the BCI method was established in 1998 additional research has been conducted to evaluate bicycling on rural routes by Jones and Carson (14) and Noel, et. al., (15.) The study conducted by Jones and Carson used a procedure developed to closely match the BCI methodology. It incorporates both geometric and operational variables considered important by adult bicyclists in terms of their comfort level when riding on rural roads in the presence of motor vehicle traffic. A web-based survey was used and the participants were asked to view numerous roadway segments captured on videotape and rate these segments with respect to how comfortable they would be cycling in the geometric and operational conditions shown. Results of the survey were analyzed using linear regression to create a rural bicycle compatibility index (RBCI) model. Noel, et. al., developed a procedure to evaluate rural segments in Quebec from a bicycle suitability point of view. This analysis placed particular emphasis on the cyclist’s perspective. A compatibility of roads for cyclist (CRC) method was developed using a survey with 200 cyclist participants. A panel of experts and officials decided to include the most important variables in the CRC model, as identified by the study participants. Unfortunately, these two procedures are not yet advanced through development efforts to the point of being widely applicable to other areas yet. Therefore, the FHWA BCI method focusing on urban and suburban was used for the SC ECG, and adapted for use on route segments exhibiting rural characteristics.

III. DATA COLLECTION

Roadway, traffic and land use data was collected on 72 sections, 234 segments and 1,615 sub-segments, delineated with respect to uniquely descriptive characteristics. This information was used as the basis for conducting an analysis of routes for the modified existing SC East Coast Greenway route. The method selected to evaluate individual segments was The Bicycle Compatibility Index, FHWA-RD-98-095 (1.) This study established a procedure for determining how roadway conditions and traffic operations impact a bicyclist's compatibility in traveling a specific section of roadway, under mixed traffic conditions (bicycles and motor vehicles.) The BCI methodology was developed with intention for use on urban and suburban road segments (mid-block locations, excluding intersections.) It incorporates an array of variables assessing the "bicycle friendliness" of a road and generally provides an indication of compatibility for other non-motorized modes likely to use the Greenway. The BCI method uses a multi-variable regression formula, which is documented in Appendix A, to calculate an index value linked with traditional Level of Service (LOS) designations, A through F, with A being the best conditions and F being the worst. BCI-LOS ranges are summarized with respect to bicycle compatibility levels in Table 2.

Table 2 – BCI Value, LOS & Compatibility Ranges
LOS BCI Range Compatibility Level
A 1.50 Extremely High
B 1.51 – 2.30 Very High
C 2.31 – 3.40 Moderately High
D 3.41 – 4.40 Moderately Low
E 4.41 – 5.30 Very Low
F > 5.30 Extremely Low

An extensive data collection and analysis effort was required to develop the robust database needed to evaluate routes and connections along the SC East Coast Greenway corridor. An overview of this process is graphically summarized in Figure 2. In addition, data sheets describing all route segments are provided in Appendix B. Each segment is represented as a line of data. The total database for the project includes 137 sections and 450 segments, with the modified existing route reflected in route maps and route tabulations, consisting of 72 sections and 234 segments. A flow chart schematic of the sections considered for the entire ECG corridor is provided in Figure 3. This diagram served as the central linkage between roadway data and geocoding, and furthermore, allowed comparison of the feasibility of possible alternative routes within the corridor. Road lengths for sections and segments were determined at the sub-segment level via GIS and are not included in the data sheets provided. As this method was developed for urban and suburban routes, several limitations and biases were noted and addressed through use of adjustments in the process. These issues are summarized as follows:

BCI Method Limitations

  • Focused on roadway characteristics and motor vehicle traffic
  • Developed for urban and suburban areas
  • Method is biased against low volume rural roads
  • Directly quantifies benefit of bike lanes and paved shoulders, however, does not readily quantify benefit of multi-use paths.

Study Adjustments

  • Developed BCI adjustment for low-volume roads below 2,500 ADT, however, based on quality control reviews, no adjustments were necessary for higher volume rural roads.
  • Converted multi-use paths to equivalent bike lane widths


Figure 2 – Overview of Data Collection and Analysis Process

 


Figure 3 –East Coast Greenway Route Section Flow Chart

IV. ROUTE ANALYSIS USING BCI

The BCI analysis was applied to the modified existing ECG and its possible alternative routes within the predefined coastal corridor. Of specific interest from an analysis standpoint is the relationship between BCI ratings and major factors such as ADT volume. A plot of this relationship is presented in Figure 4. This plot is based on all 450 route segments contained within the Greenway corridor, and not merely the 234 segments of the existing route. It is evident that BCI rating, and correspondingly LOS, deteriorates in relative proportion with increased ADT. However, an unanticipated observation was identified within the data occurring along low-volume roads, as volume approaches “0,” the BCI rating remains relatively high, evidently being affected more significantly by motor vehicle speed than by traffic volume. This problem was addressed through adjustments to the BCI procedure, described in the following sections.


Figure 4 - Average Daily Traffic versus Unadjusted BCI Rating, n = 450

Need for BCI Adjustment on Low-Volume Roads
D
ata was collected along existing and potential alternate routes within the corridor through use of an instrumented vehicle that included; video logging with corresponding audio narrative, GIS transponder unit, manual data cataloging, and photo logging of representative route conditions. Upon competition of the BCI procedure, a systematic quality control process to check ratings, location, connectivity and physical conditions of each road segment was performed. Routinely, low-volume road segments were identified in which the BCI rating, and corresponding LOS, appeared unrepresentative of actual conditions along the route. As an example of this observation, a low volume road near Purrysburgh in Jasper County is shown in Figure 11, on page 16. The initial rating for this route segment was BCI-LOS D, with a corresponding index rating of 4.11. This appears drastically different from what a cyclist would actually encounter along this picturesque roadway. It is interesting to note motor vehicle speed along this segment is 40 mph, while the ADT is merely 150 vehicles per day, based on SC DOT traffic counts. This segment is representative of the problems encountered in applying the BCI method to low-volume roads. As it was obvious that actual conditions were much more favorable than indicated, an adjustment to the BCI method was developed to address this inconsistency for low-volume road segments.

Numerical Basis for BCI Adjustment
As presented in Figure 4, it is apparent a good number of road segments contained in the database experience traffic indicative of low-volume conditions. It serves to reason, if a road has no vehiclar volume, this would create extremely high compatibility for bicycling. The question becomes, at what traffic volume threshold does bicycling encounter an extremely high level of compatibility? Wilkerson, et. al., (16) identified categories of traffic volumes, with 2,000 vehicles per day considered an upper limit threshold for the best traffic condition for bicycling. Guttenplan, et. al., (17) used a threshold value of 4,000 ADT to determine if width adjustments should be applied within a procedure to determine pedestrian and bicycle level of service along multi-modal corridors. Furthermore, based on traffic flow parameters under LOS A operation for motor vehicle traffic on two-lane roads using the Highway Capacity Manual (4,) Chapter 8 procedures, the maximum ADT generally ranges from 2,000 to 2,400 vehicles per day, depending on specific route conditions. For an ADT of 2,400 vehicles per day, this translates to a cyclist encountering approximately 2.5 motor vehicles per minute traveling in the same direction during the p.m. peak hour, and considerably less during other times of the day.

Based on this background information and knowledge of traffic engineering flow parameters, a maximum threshold value of 2,500 vehicles per day was selected, for which lower ADT values were used to adjust the BCI rating downward to better reflect the actual favorable conditions for cycling on these low-volume roadway segments. This is considered to be a relatively conservative value, and as a result of keeping this threshold as low as possible, a fewer number of segments necessitate adjustment. A careful review of BCI adjusted road segments within the SC ECG corridor, verified that the perceived BCI-LOS rating more closely matched actual route conditions. However, it should be noted that additional analysis of the database, and possibly further data collection, need to be accomplished prior to applying this threshold value to other similar projects or studies.

BCI Adjustment Procedure for Low-Volume Roads
The BCI adjustment procedure assumes that regardless of design, a road with “0” daily traffic corresponds to a BCI index rating of 1.00, and LOS A. For roads with ADT volumes between 0 and 2,500, an equivalent BCI index for 2,500 ADT volume is first calculated and then an adjustment is applied based on the actual roadway volume through straight-line interpolation. For example, given a road segment with a volume of 500 vehicles per day, which has an initial BCI of 2.84, corresponding to LOS C. First the BCI2500 index rating would be similarly calculated as 3.02. After which, an adjusted BCI value would be determined based on the total possible reduction in BCI (3.02-1.00=2.02,) assuming a theoretical condition of ‘‘0’’ traffic volume at BCI = 1.00. For the actual volume of 500, the reduction is 80% (2,000/2,500*100) thus, 80% of 2.02 is 1.62. Therefore, the adjusted BCI would be 3.02-1.62=1.4, corresponding to more representative LOS A conditions for bicycling along this low-volume stretch of roadway. In applying this adjustment procedure to the route conditions depicted in Figure 6, the initial BCI-LOS D with corresponding rating of 4.11, drops to a more indicative BCI-LOS A and corresponding rating of 1.20. This adjustment procedure was applied to all route segments with an ADT of less than 2,500 vehicles per day.

Affect of BCI Adjustment on Database
Of the 450 route segments within the SC East Coast Greenway Corridor, 89 segments were amended based on the BCI adjustment procedure developed for this data set. A plot of adjusted BCI data is presented in Figure 5. The adjustment procedure resulted in the relationship between BCI and ADT, being forced down to BCI 1.00 as ADT approaches the theoretical condition of “0” volume, with respect to the unadjusted BCI distribution shown in Figure 4. The resulting data plot now resembles a very familiar shaped curve in the filed of traffic engineering analysis, with the origin of many data functions beginning at or near the point 0,0 intercept. Table 3 provides a stratified tabulation of adjustments applied to the BCI for various volume ranges. On average the BCI-LOS for the 89 road segments was adjusted from a LOS C with corresponding index rating of 3.38, to a more realistic LOS B with corresponding index rating of 2.04.


Figure 5 - Average Daily Traffic versus Adjusted BCI Rating, n = 450 (89 route segments adjusted for ADT volumes below 2,500 vehicles per day)

 

Table 3 – Tabulation of Adjusted BCI Route Segments, N=89
ADT Volume Range Avg. BCI Avg. BCI-LOS Avg. Adjusted BCI Avg. Adjusted BCI_LOS Number of Segments
0 – 999 3.43 C 1.51 B 38
1,000 – 1,999 3.33 C 2.16 B 34
2,000 – 2,499 3.38 C 3.00 C 17
Total 3.38 C 2.04 B 89


V. SUMMARY OF EXISTING GREENWAY ROUTE IN SC

Based on the route analysis process for the SC East Coast Greenway corridor presented in Chapter 2, a variety of tabulations describing the route were developed with respect to each of the three coastal planning areas. This information is presented in Tables 4 through 9. It should be noted that the overall route length of 259 miles is greater than the 240-mile length reported in East Coast Greenway planning documents. This total length was determined from a summation of specific GIS links. However, this value is slightly inflated due to the presence of one-way bridges on US 17 in the Charleston area over both the Ashley and Cooper Rivers. In essence, GIS tabulations count each direction separately which results in padding the overall route length to a minor degree. No adjustments were made to account for this since these actually are separate roads with unique geometric features and traffic conditions. Based on information contained in Tables 3-8, the following optimistic and pessimistic aggregations are noted.

Optimistic Route Tabulations

  • 11 % (27.6 miles) of the route currently exists along either a bike lane or multi-use path. However, some of these facilities may be substandard in the current form, such as the path along the Ben Sawyer Blvd causeway connecting Mt. Pleasant and Sullivan’s Island, which is only 5-ft. wide. In addition, existing bike lane and multi-use path segments along N. Ocean Blvd. in Myrtle Beach ultimately will not be used, once multi-use path connections paralleling Carolina Bays Parkway are completed.
  • 20 % (53.0 miles) of the route currently exists along roadways that include a sidewalk. It should be noted that this tabulation also reflects multi-use paths since these facilities readily accommodate pedestrian use. Therefore, this tabulation cannot be directly added to the multi-use path length. A good example of this condition is along Grissom Parkway in Myrtle Beach where a 10-ft. multiuse path is located adjacent to the roadway. This facility is also reflected in the sidewalk tabulation.
  • 20 % (50.1 miles) of the route is located along roadways with paved shoulders. However, some of the shoulders are very narrow, for example a 2-ft. wide shoulder is present along US 17 in Georgetown County, between Pawleys Island and the Great Pee Dee/Waccamaw River bridges.
  • 51% (133.8 miles) of the route is located along roadways with motor vehicle traffic of 5,000 vehicles per day, or less.
  • 26 % (69.0 miles) of the route is located along roadways with a speed limit of 40 mph or less.
  • Based on BCI-LOS analysis, 41% (106.6 miles) of the route falls within the desirable A through C designation, with BCI value ranging from 1.11 to 3.39.

Pessimistic Route Tabulations

  • 51 % (132.1 miles) of the route exists along roadways with a speed limit of 55 or 60 mph.
  • 31% (80.7 miles) of the route exists along roadways experiencing heavy motor vehicle traffic volumes, greater than 10,000 vehicles per day, of that total, 4% (9.66 miles) are located on roads with extremely heavy traffic in excess of 40,000 vehicles per day.
  • 51 % (132.1 miles) of the route exists along roadways with a speed limit of 55 or 60 mph.
  • 59% (152.9 miles) of the route is located along roadways exhibiting BCI-LOS D, E or F. These ranges of the BCI rating are indicative of conditions that are moderately low, very low and extremely low compatibility for bicycling.
  • 13 route segments exhibiting the worst conditions along the Greenway, based on BCI-LOS F with an index rating of 5.30 or greater, comprising a total of 18.7 miles, or 7% of the Greenway length in SC. Ten segments are located along various sections of US 17.

Table 4 – Route Tabulation of Bicycle Facilities
  Lowcountry Charleston Waccamaw Total
Bike Lane 0 3.19 (3%) 3.76 (4%) 6.95 (3%)
Multi-use Path 0 10.85 (11%) 9.8 (12%) 20.65 (8%)
None 75.97 (100%) 84.32 (86%) 71.65 (84%) 231.94 (89%)
  75.97-mi. 98.36-mi. 85.21-mi. 259.54-mi.
Note: EC Greenway along modified existing route (2003) in SC. (distance in miles, % by distance)

 

Table 5 – Route Tabulation of Sidewalks
  Lowcountry Charleston Waccamaw Total
Sidewalk 1.75 (2%) 23.57 (24%) 27.73 (33%) 53.05 (20%)
None 74.22 (98%) 74.79 (76%) 57.48 (67%) 206.49 (80%)
  75.97-mi. 98.36-mi. 85.21-mi. 259.54-mi.
Note: EC Greenway along modified existing route (2003) in SC. (distance in miles, % by distance)

 

Table 6 – Route Tabulation by Shoulder Type
  Lowcountry Charleston Waccamaw Total
Grass 69.12 (91%) 64.13 (65.2%) 40.41 (47%) 173.66 (67%)
Paved 5.39 (7%) 17.59 (18%) 22.72 (27%) 45.70 (18%)
Paved w/c&g 0.45 (1%) 1.19 (1%) 2.76 (3%) 4.4 (2%)
Curb & Gutter 0.76 (1%) 3.97 (4%) 18.21 (21%) 22.94 (9%)
Parking Lane 0 2.68 (3%) 0 2.68 (1%)
Bridge w/sh 0 1.92 (2%) 1.05 (1%) 2.97 (1%)
Bridge w/o sh 0.25 (0%) 6.88 (7%) 0.06 (0%) 7.19 (3%)
Note: EC Greenway along modified existing route (2003) in SC. (distance in miles, % by distance)

 

Table 7 – Route Tabulation by Speed Limit
  Lowcountry Charleston Waccamaw Total
10 – 20 mph 0 8.68 (9%) 1.76 (2%) 10.44 (4%)
25 mph 0 5.3 (5%) 4.89 (6%) 10.19 (4%)
30 mph 0.33 (1%) 1.31 (1%) 11.2 (13%) 12.84 (5%)
35 mph 4.26 (1%) 11.97 (12%) 11.86 (14%) 28.09 (11%)
40 mph 0.76 (1%) 4.11 (4%) 2.58 (3%) 7.45 (3%)
45 – 50 mph 7.70 (10%) 22.51 (23%) 28.11 (33%) 58.32 (22%)
55 – 60 mph 62.92 (83%) 44.48 (45%) 24.81 (29%) 132.21 (51%)
Note: EC Greenway along modified existing route (2003) in SC. (distance in miles, % by distance)

 

Table 8 – Route Tabulation by ADT volume
  Lowcountry Charleston Waccamaw Total
0 – 1,000 15.5 (20%) 15.35 (16%) 10.46 (12%) 41.31 (16%)
1,000 – 2,500 22.15 (29%) 7.97 (8%) 2.68 (3%) 32.8 (13%)
2,500 – 5,000 25.36 (33%) 15.74 (16%) 18.62 (22%) 59.72 (23%)
5,000 – 10,000 7.37 (10%) 27.16 (28%) 10.45 (12%) 44.98 (17%)
10,000 – 20,000 5.59 (7%) 16.89 (17%) 11.65 (14%) 34.13 (13%)
20,000 – 40,000 0 13.39 (14%) 23.55 (28%) 36.94 (14%)
over 40,000 0 1.86 (2%) 7.8 (9%) 9.66 (4%)
Note: EC Greenway along modified existing route (2003) in SC. (distance in miles, % by distance)

 

Table 9 – Route Tabulation by BCI/LOS Rating
LOS Lowcountry Charleston Waccamaw Total
A 4.71 (6%) 20.1 (20%) 2.15 (3%) 26.96 (10%)
B 11.24 (15%) 3.83 (4%) 15.14 (18%) 30.21 (12%)
C 14.72 (19%) 17.68 (18%) 17.03 (20%) 49.43 (19%)
D 23.31 (31%) 24.57 (25%) 19.66 (23%) 67.54 (26%)
E 21.99 (29%) 22.75 (23%) 21.93 (26%) 66.67 (26%)
F 0 9.43 (10%) 9.3 (11%) 18.73 (7%)
Note: EC Greenway along modified existing route (2003) in SC. (distance in miles, % by distance)

The existing East Coast Greenway route is graphically represented for each of the three planning areas, Lowcountry, Charleston and Waccamaw) in Figures 6 through 8. It should be noted that slight modifications were made to route locations when higher volume roads along the currently planned Greenway paralleled low volume roads that were readily apparent as desirable alternate locations, prior to construction of off-road facilities. An example of this is in Charleston County, near the Town of Ravenel, where Old Jacksonboro Rd., a very low-volume 2-lane road, closely parallels US 17 for a distance justifying relocation of the Greenway route onto this more compatible low-volume, two-lane road segment. Also, existing locations of the route situated along unpaved roads were relocated for analysis purposes and evaluation consistency to nearby parallel paved routes. An example of this occurs in Jasper County, between Hardeeville and Switzerland, where the modified route was relocated for analysis purposes from Old Kings Hwy. to US 17.

Area overview maps are intended to show the general location of each area of the greenway. Details of specific routes, and possible Greenway alternatives, within each of the three coastal planning areas are presented in the following sections via larger scale maps and further discussion. The breakdown of route maps by planning region is as follows:

  • Lowcountry (Jasper, Beaufort, Colleton & Hampton Counties) – 3 route maps
  • Charleston (Charleston & Berkeley Counties) – 5 route maps
  • Waccamaw (Georgetown & Horry Counties) – 7 route maps


Figure 6 – SC East Coast Greenway, Overview Map I (Lowcountry)

 


Figure 7 – SC East Coast Greenway, Overview Map II (Charleston)


Figure 8 – SC East Coast Greenway, Overview Map III (Waccamaw)


VI. Lowcountry Region - Route Analysis

For the purpose of discussing specific route details, the SC East Coast Greenway is examined in a systematic order from south to north. As the Lowcountry Region is the southern most planning district linking the route to Savannah, Georgia, this area is presented first in the specific route evaluation. This portion of the greenway is being developed with a Revolutionary War theme, connecting a number of important historic sites including battlefields, forts, cemeteries and churches. As currently identified the route covers 76-miles through this region, and the modified existing ECG route is defined by 12 sections, 36 segments and 250 sub-segments. None of the route currently includes bike lanes or multi-use path facilities and only 2% (1.75 mi) contains an adjacent sidewalk. On a more positive note, 82% (63.01 miles) is located along low volume roads with traffic of 5,000 vehicles per day or less. Upon entering SC, the Greenway is routed inland to avoid heavily traveled roadways and problematic bridge crossings.

As shown by the map in Figure 9, the East Coast Greenway enters South Carolina from Hutchinson Island located directly across the river from the City of Savannah. It should be noted this particular configuration does not provide a landside linkage, but rather relies upon a water taxi service, which offers passage across the river. The Talmadge Memorial Bridge on US 17 allows direct access to Savannah for motor vehicles; however, the bridge currently exists as a limited access facility and prohibits non-motorized traffic. As the Greenway enters South Carolina on US 17, it crosses a bridge on the Back River that exhibits very low compatibility for bicycling, BCI-LOS E and index rating of 5.17. The route transitions from the Back River Bridge onto a section of US 17 with a 2-ft. shoulder, depicted in Figure 8. Conditions along this two-lane route segment are generally characterized by heavy traffic volume, high speeds, low compatibility for bicycling, and BCI-LOS E with a corresponding index rating of 4.92.


Figure 9 – SC East Coast Greenway, Map 1, Lowcountry (Savannah to Ridgeland)

Once the route reaches SC 170 Alt., several alternative routes were analyzed. The existing route follows US 17 and up to a point where the route turns left onto Purrysburgh Rd. and later connects with Old Charleston Rd. (shown in Figure 10,) which is very compatible for bicycling, rated as BCI-LOS A with an index rating of 1.17. However, this route section currently contains long segments of unpaved roads, such as Old Kings Hwy., shown in Figure 11. Even though the BCI rating is favorable due to very low traffic volumes, touring cyclists are likely to encounter difficulty traversing lengthy unpaved segments such as this. Application of a fine-grain wearing-surface would go a long way towards improving these road segments for bicycling. For analytical purposes and evaluation consistency a slightly modified existing route was used instead to connect through Hardeeville along US 17.

 
Figure 10 – Photo and route data for US 17 near GA State Line, Jasper County   Figure 11 – Photo and route data for Old Charleston Hwy, Jasper County

Another slight modification of the existing route was made in the Town of Ridgeland where the route was moved from US 17 to Green St., a road that exhibits BCI-LOS B and has a very high compatibility with bicycling. The route extends north along I-95 frontage roads where it merges onto US 17 for a short distance in Point South, see the map in Figure 14. From there the route turns left onto McPhersonville Rd. and continues through the Town of Yemassee as it merges onto US 17 Alt. for several miles before turning right onto Ritter Rd. and then right again onto SC 64 connecting into the Town of Jacksonboro, see the map in Figure 15. Other than the portion on US 17, all are two-lane roadways, and except for US 17 and SC 64, these segments exhibit BCI-LOS C or better providing a moderately high compatibility for bicycling. Contrasting these favorable ratings to the parallel option of traveling much more treacherous sections of US 17 through Gardens Corners and then onto Jacksonboro, this route experiences a BCI-LOS of E for the entire length and the roadway is typified by heavy traffic volumes, considerable truck traffic and high motor vehicle speeds. Road conditions and corresponding analysis data for US 17 on a segment near the Combahee River is shown in Figure 11.

 
Figure 12 – Photo and route data for Old Kings Hwy, Jasper County   Figure 13 – Photo and route data for US 17 near Combahee River, Colleton County

 


Figure 14 – SC East Coast Greenway, Map 2, Lowcountry (Ridgeland to Yemassee)

 


Figure 15 – SC East Coast Greenway, Map 3, Lowcountry (Yemassee to Jacksonboro)

 

VII. Charleston Region – Route Analysis

Within the Charleston area the modified existing ECG route covers 98-miles and is defined by 27 sections, 85 segments and 588 sub-segments. A planning study is currently underway with the objective of creating a master plan for proposed facilities need to accommodate the Greenway in Charleston County and to integrate these future facilities within an overall long-range transportation plan. Transportation consultant, Kimley-Horn & Assoicates, is in the process of conducting this study, under direction of Berkeley-Charleston-Dorchester Council of Governments, funded through a SC State Forestry Commission grant.

The route enters Charleston County on US 17 at the Edisto River Bridge. This particular section is located along a high-speed, four-lane divided roadway with no shoulder. The BCI-LOS is E with a rating of 4.85. In its current configuration, this section has a very low compatibility for bicycling. As the route approaches Parkers Ferry, Old Jacksonboro Rd. begins to parallel US 17 and this road provides an excellent option to the somewhat treacherous road environment along US 17. Favorable conditions along Old Jacksonboro Rd. accommodate a BCI-LOS A with an index rating of 1.22. Therefore, most segments of Old Jacksonboro Rd. from Parkers Ferry through the Town of Ravenel were used as the existing modified ECG route for evaluation purposed and result tabulations, see the map in Figure 16.


Figure 16 – SC East Coast Greenway, Map 4, Charleston (Jacksonboro to Johns Island)

Another option instead of using US 17, is for the route to extend along SC 174, SC 164 and SC 162. BCI-LOS ratings are generally more compatible, ranging from LOS B to D. However, all of the possible routes in this area merge back onto US 17 at Rantowles Creek where the conditions have an extremely low compatibility for bicycling with BCI-LOS F and index rating of 5.44. As this is a critical link along the Greenway route, with no alternative routes available except to move the interim route ten’s of miles inland, this section should receive a high priority. As a stopgap measure within the ECG improvement plans, provision of a paved shoulder would be very beneficial to Greenway users and motorists alike along this section of US 17, as well as the previously mentioned US 17 section near the Edisto River.

Once the route reaches the community of John’s Island, the Greenway is located along a converted rails-to-trail facility known as the West Ashley Greenway extending 7-miles into the City of Charleston, see Figure 17. This facility is unpaved but affords a welcome relief to a very poor heavily developed commercial suburban section of US 17 providing LOS F, with 6.01 BCI rating. The eastern terminus of the West Ashley Greenway occurs at an extremely busy section of Folly Beach Rd. where the route must cross amidst very complicated traffic patterns and connect to the Ashley River Bridges on US 17 which exhibit extremely low compatibility for bicycling of BCI-LOS F and a rating of 5.93, see Figure 18. Alternative routes considered in the evaluation for this area are presented in Figure 19.

 
Figure 17 – Photo and route data for West Ashley Greenway, Charleston County   Figure 18 – Photo and route data for US 17 at Ashley River Bridges, Charleston County

 


Figure 19 – SC East Coast Greenway, Map 5, Charleston (Johns Island to Charleston)

Once the route crosses onto the City of Charleston’s downtown peninsula, conditions improve dramatically for bicycling along the existing Greenway route. Lockwood Dr. contains a 10-ft. wide multi-use path, shown in Figure 20. This facility extends through waterfront land uses along the Ashley River and unfortunately includes some very narrow sections, 5-ft. in width, further constrained via concrete barrier railings on both sides. At the end of Lockwood Dr., the route transitions onto low-volume neighborhood streets and then onto a parkway setting along Murray Blvd. shown in Figure 21. These type roadways accommodate a BCI-LOS of C or better, as currently configured, based mostly on low traffic volume and low motor vehicle speed. Due to the historic nature of this area and significant right-of way constraints, it is unlikely the Greenway will be further accommodated via physical facilities along these type routes. This should be of little concern as this residential area is already very pedestrian and non-motorized mode friendly, in its currently state.

After the route rounds the tip of the Charleston peninsula and heads up E. Battery St. and E. Bay St., adjacent land use becomes more commercial and industrial as it passes port and shipping terminal facilities. Currently, the Greenway is circuitously routed onto the existing Silas N. Pearman Cooper River Bridge, which has an extremely low compatibility for cycling with a BCI-LOS F and index rating of 7.63 (second worst rating of any segment along the Greenway in the State of SC.) Fortunately, this significantly deficient segment will be rectified within a year upon completion of the new Cooper River Bridge that will include a 12-ft. wide multi-use path extending between Charleston and Mt. Pleasant. On the Charleston side the path will connect to existing roadways at E. Bay St. and some facilities would be very useful to connect the Greenway with the Concord St. loop. Otherwise the Greenway may need to be routed on an interim basis along residential streets through an economically depressed neighborhood on Charleston’s east side, due to the fact that adjacent segments on E. Bay St. experience a BCI-LOS E with a rating of 4.92. These and other routes considered as part of the evaluation for downtown Charleston are shown on the map in Figure 22.

 
Figure 20 – Photo and route data for multi-use path on Lockwood Dr., Charleston County   Figure 21 – Photo and route data for Murray Blvd., Charleston County

Heading further up the coast from Charleston, the Greenway passes through the Town of Mt. Pleasant and extends along the barrier island towns of Sullivan’s Island and Isle of Palms, before crossing back into Mt. Pleasant, see the map in Figure 23. After traversing the Cooper River Bridge, the route extends along Coleman Blvd., which contains some bike lanes as shown in Figure 24. As this section of the Greenway is located along a heavily traveled multi-lane road, the presence of a bike lane is very beneficial and improves the BCI-LOS from E to D, with an index rating improvement from 4.87 to 3.71.

After crossing scenic Shem Creek, the route passes through the Old Village of Mt. Pleasant. These residential streets are very compatible with bicycling and generally exhibit a BCI-LOS of C or better. The Greenway is then routed on a narrow, 5-ft. wide, multi-use path extending across the Ben Sawyer


Figure 22 – SC East Coast Greenway, Map 6, Charleston (Downtown Charleston)

 


Figure 23 – SC East Coast Greenway, Map 7, Charleston (Mt. Pleasant)

 

 
Figure 24 – Photo and route data for bike lane on Coleman Blvd., Charleston County   Figure 25 – Photo and route data for multi-use path on Ben Sawyer Blvd., Charleston County

causeway and connecting with the barrier island town of Sullivan’s Island. This facility accommodates a BCI-LOS of C with an index rating of 3.29. However, when the facility encounters a discontinuity in crossing the Intra-coastal Waterway movable-span bridge, the BCI-LOS decreases significantly, dropping to F with an index rating of 5.34, see Figure 25. Currently there are discussions of replacing this structure, however local residents are opposed to a high-level, fixed-span bridge and presently this impasse has slowed down development of improvement plans. Upon entering Sullivan’s Island, the route turns left onto Jasper Blvd., which intermittently contains bike lane segments and is highlighted by a beautiful new bridge extending across Breech Inlet that includes wide shoulders, 5-ft. wide bike lanes, ample sidewalk width and provides a sweeping view of the Atlantic Ocean. Once on the Isle of Palms, the Greenway contains a bike lane on one side (southbound direction) only. The route then turns left on the Isle of Palms connector, a 3-lane bridge that extends for 3-miles across tidal marsh. Even though this roadway experiences a BCI-LOS D with index rating of 3.94, the presence of 10-ft. shoulders on both sides provides conditions that are favorably perceived by the public and, correspondingly, the facility is frequently used by runners and cyclists alike. Due to increasing traffic congestion in this area, pressures are emerging from the highway and development communities to re-stripe the bridge to accommodate two-lanes in each direction, thus significantly reducing the current buffers used by non-motorized modes and correspondingly adversely affecting the BCI-LOS rating.

The Greenway route then extends along Rifle Range Rd. and Porches Bluff Rd. until merging with US 17. The route extends along US 17 for several miles under poor conditions of heavy traffic and high speeds, which exhibit extremely low compatibility for bicycling with a BCI-LOS F and index rating of 5.36. Once the route reaches the rural township of Awendaw, route parallel options are available for approximately 13-miles along adjacent low-volume, two-lane roads including Sewee Rd. and Doar Rd., which accommodate BCI-LOS of C and A respectively. Conditions on these roads are considered so favorable for cycling that local bicyclists frequently use these roads on club rides. The route then merges once again with US 17 for a long section extending all the way to the Santee River delta where the route crosses into Georgetown County. Portions of US 17 contain a narrow 2-ft. shoulder and this improves the BCI-LOS from E without a shoulder, to D with a paved shoulder.

It is worth noting that other parallel roads extending through the Francis Marion National Forest along Halfway Creek Rd. and passing by the Santee Coastal Reserve were also considered in the route analysis. Initially these roads appeared to be strong candidates for relocating the Greenway route away from heavily traveled, high-speed segments on US 17. However, since alternative parallel routes in this area all include lengthy segments on unpaved roads, typically consisting of soft sand, these routes were deemed unsuitable without provision of bicycle friendly pavement surface-course. Touring cyclists and other non-motorized modes using the East Coast Greenway would likely experience difficulty in negotiating conditions such as these. However, if pavement conditions were improved on these roads, the opportunity of avoiding poor conditions on US 17, while connecting with major points of interest such as Hampton Plantation or the fishing village of McClellanville, would render the possible use of these alternatives very advantageous. Regardless, these facilities are likely to take sometime to develop and it has been presumed that in the meantime the route would need to use roads with more durable pavement surfaces. Routes considered as part of the Greenway evaluation for the Awendaw and McClellanville area of eastern Charleston County are depicted on the map in Figure 26.


Figure 26 – SC East Coast Greenway, Map 8, Charleston (Mt. Pleasant to Santee River)

VI. Waccammaw Region – Route Analysis

Within the Waccammaw Region the modified existing ECG route covers 85-miles and is defined by 33 sections, 113 segments and 777 sub-segments. A recently completed planning study created a master plan for proposed facilities needed to accommodate the Greenway in Georgetown and Horry Counties. Planning consultant, Haden Stanzaile, conducted the study under direction of Waccamaw Regional Planning and Development Council funded through a SC State Forestry Commission grant.

The route enters Georgetown County on US 17 at the Santee River delta bridges. This particular section is located along a high-speed, four-lane divided roadway with no shoulder. The BCI-LOS is E with an index rating of 4.44. As it currently exists, this section has a very low compatibility for bicycling. The Greenway is diverted onto a scenic low-volume, two-lane loop in route to Georgetown via N. Santee River Rd, Estherville Rd. and South Island Rd. The BCI-LOS along these routes is generally C, and road conditions exhibit moderately high compatibility for bicycling. Routes considered as part of the evaluation for southern portions of Georgetown County are shown on the map in Figure 27.


Figure 27 – SC East Coast Greenway, Map 9, Waccamaw (Santee River to Georgetown)

The Greenway route merges with US 17 just prior to crossing the Sampit River Bridge, which has 6-ft. shoulders and provides a moderately compatible BCI-LOS C. Upon entering Georgetown proper, the Greenway is routed onto low-volume residential streets including Kaminski St., Front St., Cleveland St., High Market St. and St. James St., prior to merging back on US 17 on the north side of town. All of these roadways exhibit a BCI-LOS of C or better, see the map in Figure 28 for roads included in the evaluation. Leaving Georgetown on US 17, the route immediately crosses the Great Pee Dee/Waccamaw River Bridge where heavy traffic volume and high travel speeds produce a BCI-LOS E with corresponding index rating of 5.10, indicating conditions of very low compatibility for bicycling, see Figure 29.

From the bridge north to Pawleys Island, US 17 contains a narrow 2-ft. wide paved shoulder, however open road conditions lead to a BCI-LOS E and index of 4.56. Fortunately, several developers of large tracts of land on the east side of US 17 are interested in incorporating the Greenway route into their development plans, moving the facility comfortably away from this busy high-speed section of US 17. A mile or so prior to entering Pawleys Island, Kings River Rd. provides a parallel option to a relatively long stretch of US 17 extending into Litchfield Beach. This facility is a two-lane low-volume road traversing through expansive residential areas and generally providing a BCI-LOS C, see Figure 30.


Figure 28 – SC East Coast Greenway, Map 10, Waccamaw (Downtown Georgetown)

Other routes through Pawleys Island considered in the evaluation included Myrtle Ave., Waverly Rd., Library Ln., Petigru Dr. and Parkersville Rd. These routes are identified on the map in Figure 31. It is interesting to note that a short section on US 17 between S. Causeway Rd. and N. Causeway Rd. in Pawleys Island already includes a multi-use path allowing this busy commercialized roadway to accommodate a BCI-LOS C. However, this facility is not frequently used by pedestrians or bicyclists and is generally perceived by local residents as uninviting. Based on this experience, if multi-use paths are planned and constructed within the existing right-of-way along US 17, careful attention to design detail


Figure 31 – SC East Coast Greenway, Map 11, Waccamaw (Georgetown to Litchfield Beach)

will need to be created to ensure a higher type facility is provided. Inclusion of an adequate and aesthetic buffer between the multi-use path and motor vehicle travel lanes, as well as spacing and treatment of driveway crossings, are important issues to address within the context of creating a successful design.

Kings River Rd. connects with an 8-ft. wide multi-use path located in the Wilbrook Blvd. right-of-way providing a BCI-LOS B, as shown in Figure 32. This facility links to a 6-ft. wide multi-use path located along US 17 extending from Litchfield to N. Litchfield, as depicted in Figure 33. Due to heavy traffic volumes, fairly high motor vehicle speeds, frequent driveways and relatively narrow width, the US 17 multi-use path falls to BCI-LOS C. However, once this path ends traveling north on US 17, at Huntington Beach State Park, the BCI-LOS worsens to E with a rating index of 4.93, even though a narrow 2-ft. paved shoulder is present. Preliminary details for an off-road path are currently being negotiated with State Park officials that would move the Greenway away from US 17 travel lanes.

 
Figure 32 – Photo and route data for multi-use path on Wilbrook Blvd, Georgetown County   Figure 33 – Photo and route data for multi-use path on US 17, Georgetown County

The Greenway then passes through the seaside towns of Murrells Inlet, Garden City and Surfside Beach and is able to use connecting roads and streets to form a parallel alternative route to the major traffic handling facilities of US 17 and US 17 Bus., see the map in Figure 34. In the Town of Murrells Inlet, the route diverges from US 17 and follows US 17 Bus. where a 5-ft. wide bike lane is provided, see Figure 35. The route briefly converges along a major section of US 17 Bus. and then diverges onto an accommodating loop via Atlantic Ave., Ocean Blvd. and 17th Ave. A BCI-LOS C is generally provided along these routes, which exhibits moderately high compatibility for bicycling. The Greenway route merges back on US 17 and initially is able to use a short portion of frontage road. Upon merging once again with US 17 Bus., the BCI-LOS immediately deteriorates to E with an index rating of 5.05, which provides a very low compatibility for bicycling.


Figure 34 – SC East Coast Greenway, Map 12, Waccamaw (Litchfield Beach to Myrtle Beach)

 

 
Figure 35 – Photo and route data for bike lane on US 17 Bus, Georgetown County   Figure 37 – Photo and route data for multi-use path on Grissom Pkwy, Horry County

Once in Myrtle Beach, the route heads inland circumventing the airport to a point where the Greenway connects with a long section of multi-use path located along Old Socastee Hwy. and Grissom Pkwy., see map in Figure 36. A 10-ft. multi-use path provides a BCI-LOS C with an index rating of 2.38, located within the right-of-way of a 5-lane arterial roadway, see Figure 37 (on previous page.) Even though it is possible to traverse towards the beach picking up portions of N. Ocean Blvd., an undesirable transition back onto US 17 Bus/US 17 is inevitable due to the fact that a proposed off-road facility paralleling Carolina Bays Pkwy. is not yet complete. This requires the Greenway to use a heavily traveled 6/8 lane major urban arterial exhibiting the worst BCI-LOS F rating index (7.73) in the State of SC. BCI-LOS F conditions are present along this section all the way to N. Myrtle Beach, where the route diverts onto S. Ocean Blvd. via S. 48th St. and the BCI-LOS drops to a more desirable level of C, see Figure 38.

Based on the diligent efforts of local planning officials, proposed plans are well underway to extend the Greenway along a multi-use path in the right-of-way of the newly constructed, limited access, Carolina Bays Pkwy. and within an adjacent section that will meander on a separate alignment though the Lewis Ocean Bay Heritage Preserve. Additional details have been coordinated to extend the Greenway across the Intra-coastal Water way and link to existing multi-use path improvements on Grissom Pkwy. The northern section of the Greenway will link with existing path improvements recently constructed along new development roads within the Barefoot Landing Resort. This path system extends towards the beach, connecting across the Intracoastal Waterway and US 17 ultimately linking with a previously described section of the Greenway on S. Ocean Blvd. This proposed facility constitutes a crucial link in the route joining considerable portions of the Greenway that are already physically established via multi-use paths, bike lanes and related proposed facility improvements located within the cities of Myrtle Beach and N. Myrtle Beach. In addition, the Carolina Bays Pkwy. linkage would have the significant added advantage of allowing the route to circumvent and avoid the worst BCI-LOS rated road sections, along US 17, in the State of SC.


Figure 36 – SC East Coast Greenway, Map 13, Waccamaw (Myrtle Beach)

Future plans to extend the Greenway along proposed beachfront development tracts within the Town of Atlantic Beach and, as a result connecting a missing link between adjacent segments of S. Ocean Blvd., appears to be a realistic possibility. However, timing of redevelopment initiatives within Atlantic Beach is yet to be determined, therefore the schedule of providing this desirable Greenway connection is unknown. Ultimately, this linkage will negate the need to detour along the route to the inland side of US 17 for a short 6-block distance, see location map provided in Figure 39.

Once in N. Myrtle Beach, the Greenway is oriented along an alignment that avoids US 17, via S. 48th St., S. Ocean Blvd., 33rd St., Wiley Dr., 27th St., S. Ocean Blvd. and SC 9. The BCI-LOS along these routes is generally C or D. Aesthetic promenade improvements are currently being considered for S. Ocean Blvd., as well as pavement re-striping, to provide more space for non-motorized travel modes along this beachfront roadway. Either of these improvement strategies would further enhance both bicycling compatibility and pedestrian suitability on this segment of the Greenway. In addition, Hillside Dr. parallels S. Ocean Blvd. and contains, along a considerable portion of its length, a narrow 2-ft. bike lane that provides a BCI-LOS A, with corresponding index rating of 1.43, see Figure 40.

At the northern end of N. Myrtle Beach, in the Cherry Hill area, the Greenway transitions onto a 5-lane section of the Sea to Mountain Hwy., SC 9. Due to heavy traffic volumes, this road exhibits BCI-LOS E conditions with an average index rating of 4.7 on this section, providing a very low compatibility for bicycling. SC 9 crosses US 17 and the Intra-coastal Waterway, after which the Greenway route uses local streets before merging with SC 90 and then transitioning onto a busy section of US 17 that extends into the Town of Little River, see Figure 41. This segment of US 17 exhibits conditions that have an extremely low compatibility for bicycles with a BCI-LOS F and a corresponding index rating of 5.84.


Figure 39 – SC East Coast Greenway, Map 14, Waccamaw (Myrtle Beach to North Myrtle Beach)

 

 
Figure 38 – Photo and route data for S. Ocean Blvd. in N. Myrtle Beach, Horry County   Figure 40 – Photo and route data for bike lane on Hillside St., Horry County

Once in the town of Little River, the Greenway is routed onto local low-volume two-lane streets passing through residential areas offering BCI-LOS A. Unfortunately the route merges once again with US 17 for a short distance where the BCI-LOS deteriorates to F, with corresponding index rating of 6.19. Once the route turns onto SC 179, a two-lane road, and connects with a signed bike route at the NC State line, the BCI-LOS improves slightly to E with an index rating of 4.70. This concludes the East Coast Greenway route in the state covering 259-miles in length extending through cities, towns, barrier islands, rural communities and pristine environs of coastal South Carolina.


Figure 41 – SC East Coast Greenway, Map 15, Waccamaw (North Myrtle Beach to NC State Line)

 

VII. Findings and Recommendations

Data and descriptions contained in this report represent conditions of the East Coast Greenway route and corridor during the summer of 2003. Obviously progress has been made in various locations along the route since data collection efforts were completed, and some minor inconsistencies may be evident in the database used for this study. These negligible differences do not have an effect on the overall results of the study, which are intended to be a mirror of greenway route conditions at that time. The primary purpose of this study is to provide a resource to greenway supporters, agencies, advocates and decision makers, and to facilitate further development of the route. Specific details pertaining to master planning, route development and facility design are beyond the scope of this effort, and need to be addressed in separate more detailed studies. In is important to note that portions of the route are likely to exist under interim conditions for considerable periods of time into the future and reliance on linkages with the current road systems is inevitable. This study is intended to provide a better overall understanding of road linkages, a list of good routes that may suffice to accommodate the greenway as-is for many years to come, and identification of roadway sections that need timely attention to create a reasonable, functional and continual connection across the three coastal regions of the state of SC. Specific findings and recommendations are presented in the following sections.

Best Route Sections
Route segments exhibiting the best conditions along the Greenway, based on BCI-LOS A with an index rating of 1.50 or less, are identified in Table 10. A summation of these segment lengths produces a total of 26.96 miles, or 10% of the Greenway in SC. Other than the 7.97-mile section of the West Ashley Greenway in Charleston, all other BCI-LOS A segments are located along low-volume, low-speed residential or rural two-lane roads, which do not include separate multi-use paths. Segments containing multi-use paths are typically located along more heavily traveled roads that most often provide a BCI-LOS B or C. It is important to note that the BCI method evaluates how compatible bicycling is with a given roadway environment and how well cyclists can coexist under mixed traffic conditions. Obviously not all Greenway users are bicyclists and it would be desirable to accommodate other non-motorized travel modes via additional facilities that provide space outside confines of the roadway pavement or immediately adjacent shoulder.

Worst Route Sections
Route segments exhibiting the worst conditions along the Greenway, based on BCI-LOS F with an index rating of 5.30 or greater, are identified in Table 11. A summation of these segment lengths produces a total of 18.73 miles, or 7% of the Greenway length in SC. With construction of the new Cooper River Bridge in Charleston nearing completion within the next year, the second worst segment, 2.28 miles in length, will be eliminated through provision of a 12-ft. wide multi-use path as part of the bridge deck. Clearly the most glaring examples of poor conditions for bicycling compatibility are along heavily traveled segments of US 17 within the Charleston and Myrtle Beach areas. The worst rated BCI-LOS F segment, with an index of 7.73, is located along a 3.4 mile length of US 17 in Myrtle Beach and this connects with an adjacent BCI-LOS F segment extending 1.05 miles to N. Myrtle Beach. Ultimately this treacherous segment will be eliminated when a multi-use path within the right-of-way of the Carolina Bays Pkwy., and an adjacent section meandering though the Lewis Ocean Bay Heritage Preserve, is completed. This linkage constitutes a critical connection in the route that will join major portions of the Greenway already established in the cities of Myrtle Beach and N. Myrtle Beach. During the intervening, period prior to completion of the multi-use path, this segment will remain a problematic connection for those using the Greenway over an extended length. Other segments on US 17, north and south of the Charleston area, as well as on short segments within the city, exhibit BCI-LOS F conditions and need to be improved to allow disjointed existing Greenway facilities located within the area to be connected over a more considerable and serviceable distance.

Table 10– Best Route Segments Along Greenway
ID Segment (Cross Street) Location County LOS Index
W8.38 Riverview Dr (Lakeside Dr) Little River Horry
A
1.11
W8.38 Watson Ave (Mineola Ave) Little River Horry
A
1.11
C5.3 Old Jacksonboro Rd (w. of SC 174) Adams Run Charleston
A
1.22
C5.4 Old Jacksonboro Rd (e. of SC 174) Adams Run Charleston
A
1.22
C5.36 Doar Rd (US 17) Awendaw Charleston
A
1.23
W8.38 Mineola Ave (Riverview Dr) Little River Horry
A
1.25
W8.38 Lakeside Dr/US 17 Little River Horry
A
1.29
W8.38 Baldwin Ave/Watson Ave Little River Horry
A
1.29
L4.1 McPhersonville Rd (Frampton Rd) Yemassee Hampton Horry
A
1.30
W8.35 6th St (SC 90) N. Myrtle Beach Horry
A
1.35
W8.35 Morgan Ave (6th St) N. Myrtle Beach Horry
A
1.36
C5.11 Old Charleston Hwy (Main Rd) John’s Island Charleston
A
1.40
C5.11 W. Ashley Greenway (Folly Beach Rd) Charleston Charleston
A
1.40
C5.6 Old Jacksonboro Rd (Tumblestone Rd) Ravenel Charleston
A
1.42
C5.17 Chapel St. (East Bay St) Charleston Charleston
A
1.45
L1.9 Green St (3rd Ave) Ridgeland Jasper
A
1.47

 

Table 11 – Worst Route Segments Along Greenway
ID Segment (Cross Street) Location County LOS Index
W8.12 US 17 (Grissom Pkwy) Myrtle Beach Horry F 7.73
C5.21A US 17 (Cooper River Bridge) Charleston Charleston F 7.63
W8.15 US 17 (US 17 Bus) Myrtle Beach Horry F 6.65
C5.12B US 17 S (Ashley River Bridge) Charleston Charleston F 6.32
W8.36 US 17 (Baldwin Ave) Little River Horry F 6.19
W8.39 US 17 (SC 179) Little River Horry F 6.19
W8.15 US 17 (Colonial Mall Dr) Myrtle Beach Horry F 6.14
C5.12A US 17 N (Ashley River Bridge) Charleston Charleston F 5.93
C5.11 Folly Beach Rd (Wesley Dr) Charleston Charleston F 5.54
C5.9 US 17 (Bees Ferry Rd) John’s Is. Charleston F 5.44
C5.34 US 17 (Sewee Rd) Awendaw Charleston F 5.44
C5.21 Coleman Blvd (McGrath Darby Blvd) Mt. Pleasant Charleston F 5.35
C5.28 Ben Sawyer Blvd. (Intracoastal Bridge) Sullivan’s Is. Charleston F 5.34

Prioritization and Comparative Evaluation
Based on BCI-LOS analysis, 41% of the route segments fall within the desirable A through C range, while 59% fall within the undesirable D through F range. BCI index values should be useful in developing a prioritized list of essential enhancements for improving the overall East Coast Greenway route along its 259-mile length in South Carolina. Locations of critical need are easily identified though this approach. All BCI-LOS D, E and F segments should be evaluated and reviewed in detail. In some instances it may be appropriate to temporarily realign the route along more appropriate parallel roads until physical improvements can be constructed. In addition, the database contained in this study and corresponding BCI methodology can be used to analyze how effective certain types of road improvements, such as provision of paved shoulders of varying widths, would be in improving bicycling compatibility to acceptable levels. Furthermore, as SC DOT programmed improvement projects within the corridor are planned and designed, the BCI approach could be useful in evaluating how proposed projects could better meet the needs of non-motorized travel modes. For example, current bridge replacement projects on US 17 at Santee River delta, in Georgetown Co., and Rantowles Creek, in Charleston Co., are crucial links along the SC East Coast Greenway corridor, which could be configured in a manner that adequately accommodates greenway users.

Even though the goal of the East Coast Greenway Alliance is for the route to consist of 80% off road facilities, some route segments are likely to be acceptable as-is, from a functional standpoint, for the time being, allowing limited funding resources to be focused on portions of the route with the most need. Furthermore, differences between constructing a multi-use path within the right of way of a major roadway such as US 17 versus use of a parallel low-volume route that could not accommodate as extensive greenway improvements can be evaluated and reviewed on a case-by-case basis. Examples of locations where this type comparative approach would be useful include; Green St. in Ridgeland, Doar Rd./Sewee Rd. in Awendaw, and Kings River Rd. in Georgetown Co.

Design Standards
Many good technical sources are available for the planning and design of multi-use paths. AASHTO’s Guide for the Development of Bicycle Facilities (18) is the most widely recognized source for facility design criteria, however, it is intentionally vague in detail so that states have the latitude to customize concepts for their own unique conditions. Florida Bicycle Facilities Planning and Design Handbook (19) contains a chapter on design of shared path, which provides a very useful commentary on a host of intangible issues that should be addressed in path development to create an optimal facility that is effective on a variety of levels. A number of other design documents are also available for addressing facility development issues (20, 21, 22.) Figure 42 provides AASHTO compliant criteria for the design of separate multi-use path facilities. In essence the path should be designed as a mini-roadway with its own horizontal alignment and vertical profile grade line. Cross-section consistency along the facility length is important with respect to shoulders, clear zones and surface drainage features. The buffer width and distance between the multi-use path and adjacent travel lanes is one of the most crucial issues for user comfort and positive user perception. AASHTO allows this buffer to be as little as 5-ft., however, extending this dimension to as wide as feasibly possible is desirable to improve the path environment and enhance the user’s experience. Accommodating this objective can have the adverse effect of increasing project costs, as an increased buffer dimension typically places the multi-use path in direct conflict with existing drainage facilities.

The importance of providing a durable and uniform surface course treatment for multi-use paths is a paramount consideration in creating a usable facility. Minimum pavement thickness for paths is typically recommended to be 7 to 15 cm (3 to 6 in.) for asphalt and 4 to 5 cm (1.5 to 2 in.) for concrete, assuming proper sub-grades and base courses have been constructed (21, 22). These depths are generally based on the minimum lifts at which paving materials can be constructed using conventional means. To provide longer durability, lower maintenance subsequent costs and address the contingency that additional loading may occur through non-design vehicle use, it is recommended that these minimum dimensions be increased and that special attention be given to base and sub-base materials. With regard to asphalt pavements, design criteria for use of high asphalt content to reduce thermal cracking as in low volume road appears most appropriate for bicycle path design.


Figure 42 – Cross Section Design Criteria for Multi-use Greenway Path
NOTES
1. The horizontal alignment should be established through use of a coordinate system which clearly defines all bearings, PI locations, tangent dimensions, deflection angles, PC & PT stations, circular curve data, superelevation transition limits and reference point locations.
2. The vertical alignment should detail tangent grades, VPI locations, vertical curve lengths, VPC & VPT locations, profile grade elevations and clearance dimensions to underground utilities.
3. A drainage ditch or swale should be provided adjacent to the shoulder when needed to intercept surface runoff and prevent water from flowing across the bikeway. Cross culvert drainage structures should be located as necessary to carry flows along existing watercourses.
4. Toe of slope should include provisions to insure runoff is not trapped and will flow towards drainage courses.
5. Separation distance should be a large as possible, with AASHTO stating 5-ft. min. Buffer treatments such as trees, landscaping, barriers, etc. are highly desirable to improve user comfort and path perception.

Interim Greenway Use
Bicyclists and others are already beginning to travel lengthy stretches of the Greenway. Upon entering SC, Greenway users find a very small number of route segments containing physical improvements, as envisioned by the East Coast Greenway Alliance. Therefore, most linkages along the corridor need to be made along existing streets and roads. Due to the nature of transportation funding sources and allocation constraints, it is understood that facility improvements will be constructed in phases over a relatively long period of time, similar to the interstate highway system of the 1960’s and 1970’s. This will require Greenway users to rely upon use of on-road connections for years to come. Fortunately some road segments already provide an acceptable environment for cycling, with 41% of road segments along the modified existing route falling within BCI-LOS A through F. It would be reasonable to concentrate much of the initial funding sources available for Greenway improvements to the other 59% of the route. Segments that provide acceptable levels of compatibility for bicycling could be used as-is during the intervening period while more pressing problem areas are addressed within a more compressed time frame. Examples of good existing route segments include McPhersonville Rd., in Hampton Co., Pitt St., in Mt. Pleasant, and High Market St., in Georgetown. Regardless of the approach, timely attention needs to be focused on creating a reasonable, functional and continual connection across coastal regions of SC within a near-term planning horizon.

Multiple Route Branches within Greenway Corridor
With the need to connect various points of interest and accommodate differing user types, pressures to create multiple branches of the Greenway have emerged. Examples of these issues include; an ECG connection to Beaufort via the newly constructed Broad River Bridge on SC 170, connecting the ECG route along Mathis Ferry Rd. or Rifle Range Rd. in Mt. Pleasant in addition to the barrier island route, and extending the route along Carolina Bays Pkwy. in addition to the N. Myrtle Beach connection. The East Coast Greenway Alliance has a process in place to deal with evaluation and designation of alternative and spur routes. The focus of this study has been along what is referred to by the Alliance as the spine route. It is oblivious that once such a significant facility is completed, numerous local trail and path systems will benefit from connecting to the Greenway allowing longer non-motorized trips to occur within urban, suburban and rural areas.

Differing User Types
A wide variety of user types are anticipated to use the East Coast Greenway. Travel modes and Greenway uses are expected to include; bicycling, walking, wheelchair use, hiking, jogging/fitness, in-line skating, back packing, nature appreciation and other similar uses. A separate path, as endorsed by the National East Coast Greenway Alliance, is likely to best accommodate such a diverse collection of anticipated greenway users. The BCI-LOS methodology, used as the analytical basis for conducting this study, is focused on one of the primary Greenway travel modes assessing "bicycle friendliness" along connecting road segments. Results from this assessment are generally believed to provide a helpful surrogate indicator of route compatibilities for other non-motorized travel modes, which are likely to use the Greenway.

Greenway User Input
A number of organized groups, advocate alliances and potential recreational users have a significant vested interest in development of facilities for the East Coast Greenway. These groups have the potential of being extremely effective in providing decision makers with supportive input through avenues available within the local transportation planning process. Favorable public input is often a crucial component in obtaining timely project funding and in receiving priority treatment amidst the vast sea of community transportation needs. Interest groups are likely to include bicycle clubs, running clubs, advocacy groups, nature clubs, hiking clubs and other recreational groups. Rather than merely handing these groups a completed plan of the Greenway, it would be much more desirable to allow them input into the project development process, possibility through the use of surveys, special presentations, forums and other approaches to solicit meaningful feedback and create interactive dialogue. Bicycle clubs could provide direct feedback on road conditions, facility design details, popular local destinations, trail head/access points, promotion/events, etc. This appears to be an obvious connection that is yet to be made for improving the overall concept and Greenway implementation plan that best meets the goals of the national alliance and serves the needs of local communities.

Partnerships
A project of this magnitude requires a great deal of coordination and support from a variety of sources. Physical improvements are likely to be constructed in a variety of locations including: State DOT right-of-way along either primary or secondary roads, city/town street right-of-way, publicly owned recreational/preservation lands and commercial/residential development property. Probably the two most critical partnership connections occur at the State DOT level and regional council of governments level. The SC State DOT is responsible for roads and route segments along the predominate length of the Greenway. Improvements their agency is able to incorporate into typical road projects within the greenway corridor, as well as other more targeted projects they can initiate, for the sole purpose of enhancing the Greenway environment, will be a crucial link in the progress of developing the proposed route over the years to come. The role of regional transportation planning organizations is already being addressed to a considerable degree through current Greenway master plan initiatives. These efforts will hopefully create a mechanism for local governments in each respective region to understand the importance of creating consistent linkages and a uniform design environment, and lead communities begin to embrace and develop portions of the greenway in their jurisdictions.

Further Improvements to BCI Methodology
In evaluating route data and BCI-LOS results from the 450 road segments within the SC East Coast Greenway corridor, problems were identified in the low-volume portion of analysis range. This was addressed through an adjustment founded upon a conservative maximum threshold ADT value of 2,500 vehicles per day. Additional research should be conducted to determine the sensitivity of this value to cyclist perception. Cyclist surveys could be used, or simulated road conditions could be depicted, and data could be collected and correlated with route data already obtained. Other BCI-LOS improvements could focus on addressing the relative compatibility of providing a multi-use path within the road right-of-way. For the few segments in the SC East Coast Greenway corridor containing multi-use paths, the width was converted into an equivalent single direction width of bike lane and used in the current BCI formula. Results produced expected comparative results, however a specific method to incorporate multi-use paths into the formula would be more desirable.

Conclusion
In conclusion, development of the East Coast Greenway in the coastal areas of South Carolina is a major undertaking requiring considerable coordination and resources. This study is intended to document the status of the current route within the broadly defined corridor and to help provide planners, engineers and transportation officials with a database useful in identifying the most pressing improvement needs currently evident along the 259-mile greenway in SC. In the years ahead, successful development of this wide-reaching and environmentally-visionary multi-state transportation facility will constitute a major asset to outdoor enthusiasts and residents in SC coastal areas, as well at many others along the entire Atlantic Ocean seaboard of North America.

Acknowledgement
The authors would like to express their appreciation to the South Carolina State University, James E. Clyburn University Transportation Center, for their support and funding of this research study, with special gratitude to Center Director, Dr. Clarence Hill, for his encouragement and direction. Completion of this project was made possible though the dedicated efforts, hard work and valuable contributions of students in the Transportation M.S. program at Clemson University.

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Appendix A – Summary of Bicycle Compatibility Index (BCI) procedure

Appendix B – Database and BCI rating for SC ECG route segments