U.S. Department of Transportation
Federal Highway Administration
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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations
|This report is an archived publication and may contain dated technical, contact, and link information|
Publication Number: FHWA-HRT-05-138
Date: July 2006
Shared-Use Path Level of Service Calculator
A User's Guide
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7. EXAMPLE APPLICATIONS: FICTIONAL CASE STUDIES
CASE STUDY 1: TESTING DESIGN OPTIONS FOR THE STONE CREEK TRAIL UPGRADE
Stone Creek Trail is located in the heart of Rockton, an old, eastern industrial city of about 200,000 residents. The 25-year-old trail is located in a linear park that was developed along a large stream, Stone Creek. Downtown Rockton grew at the confluence of Stone Creek and the Rocky River. The trail is 8.8 km (5.5 mi) long and connects a number of the city's finest neighborhoods with downtown. Along it are located an elementary and junior high school, a major playground, a small hospital, and a small liberal arts college. When it was last repaved 15 years ago, it was widened from the previous 1.8-m or 2.1-m (6.0-ft or 7.0-ft) width to 2.4 m (8.0 ft) throughout.
In recent years, the city council and managing agency, Rockton Department of Public Works and Parks (DPW&P), have been receiving pressure to widen the trail even further. That pressure was coming from a number of community interests:
The Stone Creek Park Committee, a longstanding advisory committee for DPW&P, favors some widening but is wary of making the trail so wide that too many trees are lost and the 100-year-old park will become a speedway for wheels. There is concern that too many wheeled users will make the park and trail too scary for senior citizens and others (mostly walkers) who have cared for it for many years. Segregation of users is one possibility they are considering, but they are not sure users will comply.
The question is this: How much more width is enough to satisfy the demand and how much is too much? An initial staff survey determined that, in most parts of the park, enough space exists to accommodate a trail of up to 4.3 m (14.0 ft) wide. The DPW&P staff and the committee would like to know what other communities in similar situations have done. However, even on the Internet, they had difficulty finding another community with enough similar characteristics that had already encountered and solved a similar trail problem. Then, in response to a call to the State, the Bicycle and Pedestrian Coordinator at the State department of transportation recommended the Shared-Use Path LOS Calculator, a new FHWA resource.
Because the community had no existing trail counts, nor were any useful volume counts available from other multiuse trails in the State, it was necessary to gather fresh trail user counts to develop inputs for use of the tool. Volunteers from all of the interested stakeholder groups were organized, and they followed the trail count guidelines provided in the SUPLOS User's Guide. To meet the data needs necessary for the results they wanted, the following data collection scope was adopted:
Figure 2, a screen capture from the Shared-Use Path LOS Calculator for this case, shows the results of the average weekend, one-way, per-hour, volume counts, and mode splits. Friday volumes were found to be about 50 percent lower and so were not used for the LOS calculations. As noted above, for data collection and analysis purposes, the trail was divided into five segments. Trail segments 1 and 2 scored F and E levels of service, respectively, while the other segments scored D, confirming suspicions that peak-hour conditions were deteriorating. It was easy for the staff and committee to imagine even worse conditions on summer weekends when more tourists were in town.
Before various widths were tested, participants agreed that if the trail were widened, it should be done not only to improve conditions for existing users, but also to secure some additional capacity for future growth in trail use.
1 ft = 0.3 m
Figure 2. Screen capture. Existing conditions LOS analysis.
The following general LOS goal and design policy was adopted:
Using these guidelines, a variety of widths was tested in the calculator to see which achieved the desired levels of service. Figure 3, a screen capture from the Shared-Use Path LOS Calculator for this case, shows the widths and resulting LOS scores that were finally selected.
Figure 3. Screen capture. LOS for selected design widths.
1 ft = 0.3 m
Working with a trail design consultant, the widths in figure 3 and the general guidelines were used to develop five different cross-sections. Designs for segments 2 and 4 varied only in the centerline treatment, as a means to further test users' response. Table 9 describes the final segment designs selected.
Table 9. Selected cross sections
CASE STUDY 2: TESTING DESIGN OPTIONS FOR THE DE SOTO RIVER WATERFRONT TRAIL
The De Soto River Trail is a 7.2-km (4.5-mi) segment of multi-use trail proposed for the downtown waterfront in the city of New Metropolis. It will extend the existing De Soto River Trail, a 24.2-km (15.0-mi) trail system, from a nearby suburb into the heart of the city. New Metropolis is a city of 500,000 people in a metropolitan area of approximately 1.5 million.
The Waterfront Trail has been an idea in the city's comprehensive plan for many years; however, no action was taken until a waterfront revitalization effort brought the idea to prominence. Currently, a detailed waterfront redevelopment plan is underway and the city's Office of Planning wants to ensure that the trail component of this plan establishes appropriate path design guidelines. Because it is the first major shared-use path to be built in the city for 25 years, the city's transportation and park departments have no pre-existing guidelines and little trail experience. An advisory committee has been formed to assist the Office of Planning and revitalization consultants with the trail plan.
The major question facing the Waterfront Trail Advisory Committee (WTAC) is this: How wide must the trail be to serve the volumes and diverse user groups expected? A WTAC member suggested using a new resource developed by USDOT-funded research called the Shared-Use Path LOS Calculator. The following discussion describes how WTAC used the calculator to inform their design process.
After reading in the User's Guide how the LOS concept should be applied to a trail with various access points, WTAC recognized that a LOS evaluation should be performed for three separate segments:
Given the history of the De Soto River Trail in neighboring Jefferson County, it seemed logical to employ trail usage data from that trail, at least as a starting point for volumes and user mixes that might be expected on the city's section of the trail.
The existing De Soto River Trail is a 3.0-m (10.0-ft) wide asphalt path. Counts taken the previous year show that the trail is averaging about 250 users per hour (total 2-way volume). The mode split for various trail user types was as follows:
The volume data provided by Jefferson County were generated by taking counts every hour between 12:00 p.m. and 4:00 p.m. on one nice-weather weekend in both the spring and fall. The location where these counts were taken is just outside the city, along a 2.4 km (1.5-m) segment between a large trailhead near the city limits and a Jefferson County regional park facility in Jeffersonville (a suburb of 85,000 people). Based on this volume and mode split data, the calculator gave the existing De Soto River Trail in Jefferson County a LOS score of 2.81, which is a high D.
Because the Waterfront Trail will be located in the city, which has higher population density and fewer trail opportunities than suburban Jefferson County, WTAC wants a plan to accommodate higher future-use levels. As a result, WTAC developed the following adjustments to the Jefferson County baseline counts, upon which to base assumptions for LOS analysis of segments A–C:
Using these assumptions, the Office of Planning staff developed a series of volume and mode split estimates to use as inputs into the Shared-Use Path LOS Calculator to develop potential trail design cross sections for segments A–C of the Waterfront Trail, as shown in table 10.
Table 10. Volume and mode split estimates to test in the calculator.
Various widths were tested in 0.2-m (0.5-ft) increments, starting at 2.9 m (9.5 ft). With each width change, the LOS score was observed to determine when a low-C (3.0-3.2) was achieved. It took 6.1 m (20.0 ft) width to get a low-C for segment C. Because 6.1 m (20.0 ft) was considered too wide a footprint, a multiple treadway design was considered that would provide pedestrians and runners with their own dedicated treadways. An 80 percent compliance rate was used for pedestrians and runners, and the user volume and mode splits were reduced accordingly. Figure 4, a screen capture from the Shared-Use Path LOS Calculator for this case, shows the results from the calculator after revising segment C for multiple-treadway options.
Based on these results, WTAC adopted the following width design guidelines for each trail segment:
Figure 4. Screen capture. LOS for 10-year projected volumes and selected design widths.
1 ft = 0.3 m
To ensure the potential to serve higher than expected volumes of trail users in the future, the following recommendations were included in the design guidelines: