Evaluation of Safety, Design, and Operation of Shared-Use Paths, Final Report

July 2006

FHWA-HRT-05-137

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U.S. Department of Transportation
Federal Highway Administration

Research, Development, and Technology
Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, Virginia 22101-2296

FOREWORD

Shared paths are paved, off-road facilities designed for travel by a variety of nonmotorized users, including bicyclists, pedestrians, skaters, joggers, and others. Shared-path planners and designers face a serious challenge in determining how wide paths should be and whether the various modes of travel should be separated from each other. Currently, there is very little substantive guidance available to aid in those decisions.

This document describes the development of a new method to analyze the quality of service provided by shared paths of various widths and the accommodation of various travel-mode splits. The researchers assembled the new method using new theoretical traffic-flow concepts, a large set of operational data from 15 paths in 10 cities across the United States, and the perceptions of more than 100 path users. Given a count or estimate of the overall path user volume in the design-hour, the new method described here can provide the level of service for path widths from 2 to 6 meters (8 to 20 feet).

The information in this document should be of interest to planners, engineers, parks and recreation professionals, and to others involved in the planning, design, operation, and/or maintenance of shared paths. In addition, this document will be of interest to researchers investigating how to analyze multiple modes of travelers in a finite space with minimal traffic control. This document describes a spreadsheet calculation tool called SUPLOS that was also developed as part of the same effort, and this tool is being circulated by the Federal Highway Administration (FHWA).

Michael F. Trentacoste
Director, Office of Safety
Research and Development

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. This report does not constitute a standard, specification, or regulation.

The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers' names appear in this report only because they are considered essential to the objective of the document.

QUALITY ASSURANCE STATEMENT

FHWA provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

Form DOT F 1700 Reproduction of completed page authorized.

SI* (Modern Metric) Conversion Factors

TABLE OF CONTENTS

1. Introduction
   • Shared-Use Paths
     • Definition
     • Gaining Popularity
   • Problems Facing Designers
     • Existing Level of Service (LOS) Method
     • Limitations of Current LOS Method
   • Project Objective
   • Project Methods
     • Development of Theory
     • Operational Data Collection
     • Perceptual Data Collection
     • A Usable Procedure
   • Project Scope Limited
   • Research Products
     • Description of the Products
     • Intended Users
   • Report Format
2. Literature Review
   • Introduction
   • Path User Characteristics
     • Pedestrian Characteristics
     • Bicyclist Characteristics
     • Other Path Users
   • Measuring Path User Quality of Service
     • Hindrance
     • Density
     • Space
     • Stress
     • Current LOS Scales
     • Other Ways To Set the LOS Scale
   • Summary
3. Development of Theory
   • Introduction
   • Estimating the Number of Events
     • Glossary of Variables
   • Estimating Active Passing Events
     • Extension to Exclude Marginal Active Passing Events
     • Estimating the Number of Passive Passing Events
     • Extension to Exclude Marginal Passive Passing Events
   • Estimating the Number of Meetings
     • Sensitivity of Passing Events to Key Parameters
   • Estimating the Probability of Delayed Passing
     • Delayed Passing on Three-Lane Paths
     • Delayed Passing on Four-Lane Paths
     • Multimodal Delayed Passing Probability
     • Numerical Application of the Delayed Passing Models
4. Operational Data Collection
   • Introduction
   • Data Collection Method
     • Equipment
   • Site Selection
   • Data Collection Execution
5. Operational Data Analysis
   • Introduction
   • Average and Default Values
     • Speed
     • Volume and Mode Split
     • Peak-Hour Factor
     • Users Occupying Two Lanes
     • Distance Needed to Pass
     • Validating Theory
   • Speeds Normally Distributed
   • Comparing Predicted Meetings and Passings to Field Data
6. Perception Data Collection
   • General Rationale
   • Participants
   • Collection of User Perception Data
     • Structure and Content of the Survey Instrument
     • Format of Participants’ Responses
7. Analysis of Perception Survey Responses
   • Introduction
   • Data Overview
     • Demographic Variables
     • Path Design Variables
     • Events on the Path
     • Video Quality
   • Model Creation
     • Interactions
     • Choice of Overall Response
     • Fitting the Model
8. LOS Procedure
   • Introduction
   • Types of Shared-Use Paths To Which This Study Applies
   • LOS Defined
   • The Perception Survey Response Scale
   • Developing the LOS Procedure
     • Start With the Model from Chapter 7
     • Model Does Not Cover All Combinations
   • Delayed Passing Adjustment
     • Adjustment for Low Number of Events
     • Putting It All Together
     • Comparison to HCM Method
   • Applying the Model
     • Link Analysis
     • Data Requirements
     • Assumptions and Default Values
   • LOS Lookup Tables
     • Instructions for Using the LOS Calculator
     • Implications for Trail Design
     • Trail Width
     • Centerline Striping
     • Multiple Treadways
     • Trail Operations and Management
   • Case Studies
9. Conclusions and Recommendations
   • Introduction
   • Conclusions
   • Recommendations
     • Marketing the New LOS Procedure
     • Future Research Needs

Appendix A. Perception Survey Fact Sheet and Informed Consent Form

Appendix B. Perception Survey Background Information Form

Appendix C. Screen Shots From Perception Study Video

References

LIST OF FIGURES

• Figure 1. Schematic for active passing estimation.
• Figure 2. Schematic for passive passing estimation.
• Figure 3. Schematic for meeting event estimation.
• Figure 4. Sensitivity of hourly passing rates to individual bicyclist speed.
• Figure 5. Sensitivity of hourly passing rates to directional flow rates.
• Figure 6. Delayed passing cases on a two-lane path.
• Figure 7. Schematic of delayed passing on a three-lane path.
• Figure 8. Schematic of delayed passing on a four-lane path.
• Figure 9. PHF as a function of hourly volume.
• Figure 10. Distribution of bicycle speed data.
• Figure 11. Distribution of pedestrian speed data.
• Figure 12. Distribution of skater speed data.
• Figure 13. Distribution of jogger speed data.
• Figure 14. Distribution of child bicyclist speed data.
• Figure 15. Average meetings and passings per trail related to average user volume.
• Figure 16. Model prediction versus field data for meetings based on volume groups.
• Figure 17. Model prediction versus field data for meetings based on speed groups.
• Figure 18. Model prediction versus field data for passings based on volume groups.
• Figure 19. Model prediction versus field data for passings based on speed groups.
• Figure 20. Representative response format.
• Figure 21. Effects of respondent age on overall rating.
• Figure 22. Effects of respondent gender on overall rating.
• Figure 23. Effects of path user type on overall rating.
• Figure 24. Effects of respondent health status on overall rating.
• Figure 25. Effects of respondent path use on overall rating.
• Figure 26. Effects of path width on overall rating.
• Figure 27. Effects of the number of meetings on overall rating.
• Figure 28. Effects of the number of active passings on overall rating.
• Figure 29. Comparison of recommended new LOS procedure to 2000 HCMprocedure for a 2-m- (8-ft-) wide (two-lane) path with no centerline.
• Figure 30. Comparison of recommended new LOS procedure to 2000 HCMprocedure for a 3‑m- (12-ft-) wide (three-lane) path with no centerline.
• Figure 31. Fact sheet for conformed consent.
• Figure 32. Lake Johnson Trail.
• Figure 33. Sammamish River Trail.
• Figure 34. Mill Valley-Sausalito Pathway.
• Figure 35 White Rock Lake Trail.
• Figure 36. Lakefront Trail.
• Figure 37. South Bay Trail.
• Figure 38. Forest Park Trail.
• Figure 39. Honeymoon Island Trail.
• Figure 40. Minuteman Bikeway.
• Figure 41. Dr. Paul Dudley Bicycle Path.

LIST OF TABLES

• Table 1. LOS examples for a two-way, shared-use path.
• Table 2. Bicycle LOS criteria for shared-use paths in the 2000 HCM.
• Table 3. Pedestrian LOS criteria for 2-m- (8-ft-) wide shared-use paths in the 2000 HCM.
• Table 4. Average flow pedestrian walkway LOS criteria from the 2000 HCM.(4)
• Table 5. Computational spreadsheet for active passing events.
• Table 6. Computational spreadsheet for passive passing events.
• Table 7. Computational spreadsheet for meeting events.
• Table 8. Numerical illustration of path-width effect on delayed passing.
• Table 9. Characteristics of operational study sites.
• Table 10. Additional characteristics of operational study sites.
• Table 11. Number of successful data collection runs by trail.
• Table 12. Speeds by mode and trail (all speeds in mi/h).
• Table 13. Volumes and mode splits by trail.
• Table 14. PHF data.
• Table 15. Distance needed for a bicycle to pass a pedestrian.
• Table 16. Summary of distance needed to pass values.
• Table 17. Chi-square test results comparing field and normal distributions for speed data.
• Table 18. Average meetings and passings on each trail.
• Table 19. Statistical test comparing meetings estimated by model to field data for volume groups.
• Table 20. Statistical test comparing meetings estimated by model to field data for speed groups
• Table 21. Statistical test comparing passings estimated by model to field data or volume groups.
• Table 22. Statistical test comparing passings estimated by model to field data for speed groups.
• Table 23. Distribution of subjects by age.
• Table 24. Distribution of reports of individual health status.
• Table 25. Distribution of individuals’ estimated frequency of riding and/or walking for either recreational and/or fitness purposes.
• Table 26. Estimates of shared-path use.
• Table 27. Characteristics of the 36 perception data collection video clips.
• Table 28. Average ratings of each video clip.
• Table 29. Effects of other path design variables on average ratings.
• Table 30. Effects of video quality on average ratings.
• Table 31. Correlation between the four perception measures.
• Table 32. Analysis of variance table for the final model.
• Table 33. Parameter estimate table for the final model.
• Table 34. Correspondence between perception score and LOS.
• Table 35. Scores and levels of service based only on equation 61.
• Table 36. Scores and grades based on complete LOS procedure.

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HRT-05-080

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