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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-04-103
Date: October 2004

Characteristics of Emerging Road and Trail Users and Their Safety

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Federal Highway Administration

Research and Development

Turner-Fairbank Highway Research Center

6300 Georgetown Pike

McLean, VA 22101


Throughout the United States, there has been a dramatic increase in the varieties and numbers of nonmotorized users on trail and roadway facilities. Kick scooters, inline skates, hand cycles, recumbent bicycles, and other emerging users are now commonly seen sharing space with bicycles and pedestrians on roadways and shared use paths. Urban trail operators are reporting operational and safety problems associated with the increasing number of emerging users and their operational needs. User groups are petitioning State legislatures and local governments to legally operate their nonmotorized vehicles on roadways. The guidelines provided in the American Association of State Highway and Transportation Officials (AASHTO) Guide to the Development of Bicycle Facilities are based on the physical dimensions and operating characteristics of bicycles only and may not meet the needs of emerging trail users. To address these issues, the Federal Highway Administration (FHWA) sponsored this study to better understand the physical dimensions and operational characteristics of an increasingly diverse group of nonmotorized trail and roadway users.

The results of this study can be used to help design professionals adequately design roadway and shared use path facilities to meet the operational and safety needs of a more diverse group of users.

Michael Trentacoste

Director, Office of Safety

Research and Development


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.

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

The Federal Highway Administration (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.

Technical Report Documentation Page

1. Report No.
2. Government Accession No. 3. Recipient's Catalog No.
4. Title and Subtitle
Characteristics of Emerging Road and Trail Users and Their Safety
5. Report Date
October 2004
6. Performing Organization Code
7. Author(s)
Bruce W. Landis, Theodore A. Petritsch, and Herman F. Huang
8. Performing Organization Report No.
9. Performing Organization Name and Address
Sprinkle Consulting, Inc.
18115 US Highway 41 North, Suite 600
Lutz, FL 33549
10. Work Unit No. (TRAIS)
11. Contract or Grant No.
12. Sponsoring Agency Name and Address
Federal Highway Administration
Turner-Fairbank Highway Research Center
6300 Georgetown Pike McLean, VA 22101
13. Type of Report and Period Covered
Final Report January 2002-January 2004
14. Sponsoring Agency Code

15. Supplementary Notes

Contracting Officer's Technical Representative (COTR): Ann Do, Office of Safety Research and Development, HRDS-06

16. Abstract

This study was undertaken to clarify the operational characteristics of an increasingly diverse group of trail and other nonmotorized transportation users. Three "Ride for Science" data collection events were conducted to obtain the physical dimensions, turning capabilities, lateral operating space, acceleration, speed, and stopping sight distance of trail users. The results confirmed the great diversity in the operating characteristics of various road and trail user types. Some examples of findings include:

Sweep Width-The 85th percentile inline skater had a 1.5-meter (m) (4.9-foot (ft) sweep width, wider than the AASHTO recommended width for bike lanes.

Design Speed-Recumbent bicyclists had the highest observed 85th percentile speeds of 29 kilometers per hour (km/h) (18 miles per hour (mi/h)), less than AASHTO's minimum design speed.

Horizontal Alignment-Most users did not reduce their speeds for turning radii greater than 16 m (52.5 ft).

Stopping Sight Distance-A recumbent cyclist in the 85th percentile requires a stopping sight distance of 32.7 m (107.3 ft) on wet pavement, less than the AASHTO value.

Vertical Alignment/Crest Vertical Curves-Recumbent bicyclists had a required length of a crest vertical curve of 46.7 m (153 ft), less than the AASHTO value.

Signal Clearance Intervals-Five-second clearance intervals would provide insufficient time for most users (85th percentile users) to clear a five-lane (18.3-m (60-ft) wide) intersection.

Characteristics of Segway® Users-Many characteristics of Segway users were comparable with those of other emerging trail users. These findings suggest that design guidelines may need to be revised to incorporate the needs of emerging trail users. The results of this study can be used to help design professionals adequately design roadway and shared use path facilities to meet the operational and safety needs of this growing group of users.

17. Key Word
Bicyclists, emerging users, AASHTO, operating characteristics, shared use paths
18. Distribution Statement
No restrictions.
19. Security Classif. (of this report)
20. Security Classif. (of this page) Unclassified

21. No. of Pages

22. Price

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

SI* (Modern Metric) Conversion Factors











Design of Shared Use Paths, Street Intersections, and Midblock Crossings





Figure 1. An inline skater

Figure 2. Nonmotorized kick scooters

Figure 3. Jogging stroller for two

Figure 4. Tandem bicycle

Figure 5. Recumbent bicycle

Figure 6. A Segway user

Figure 7. Manual wheelchair

Figure 8. Another manual wheelchair

Figure 9. Power wheelchair

Figure 10. Assistive powered scooter

Figure 11. Hand cycle

Figure 12. Another hand cycle

Figure 13. Racing wheelchairs

Figure 14. Off-road racing wheelchair

Figure 15 Another off-road racing wheelchair

Figure 16. Pinellas Trail, St. Petersburg, FL

Figure 17. Paint Branch Trail, College Park, MD

Figure 18. San Lorenzo River Trail, Santa Cruz, CA

Figure 19. Typical layout of data collection stations (San Lorenzo River Trail)

Figure 20. Trail users consisted of both active and in situ participants

Figure 21. Trail user intercept signage

Figure 22. Video cameras were setup to record participant movements at Stations 3 through 7

Figure 23. Equipment testing at data collection stations

Figure 24. Temporary pavement markings were tested

Figure 25. Registration desk

Figure 26. Physical measurements

Figure 27. Three-point turn

Figure 28. Participant within turning radii station

Figure 29. Turning radius layout (not to scale)

Figure 30. The participants were briefed at the turning radius station

Figure 31. Research staff oversaw the turning radius station to ensure proper participant flow-through

Figure 32. A participant traveling through the largest radius path

Figure 33. Participants traveling through progressively smaller turning radii

Figure 34. Participants accelerated along a 60-m (200-ft) section of the course

Figure 35. Participants were asked to accelerate to their normal speed

Figure 36. A skateboarder starting to accelerate

Figure 37. Sweep width station

Figure 38. Sweep width and speed

Figure 39. Speed (and sweep width) station

Figure 40. Stopping sight distance

Figure 41. Several video cameras were positioned at strategic points around the braking area

Figure 42. STOP sign controller signaling a bicyclist to stop

Figure 43. The study reveals important information on various users now common on shared use paths

Figure 44. Thirty-two hand cyclists were active participants in this study

Figure 45. Two tandem riders negotiating a curve at the turning radius station

Figure 46. Trail users have diverse operating characteristics

Figure 47. AASHTO's design bicyclist travels at 30 km/h (20 mi/h)

Figure 48. The longest users observed in this study exceeded 2.4 m (8 ft) in length and should be considered the critical users

Figure 49. A hand cyclist

Figure 50. Segway users at the physical measurements station

Figure 51. A Segway user on the Paint Branch Trail in Maryland

Figure 52. Segway in the turning radius station

Figure 53. Many users of various ages and abilities participated in each "Ride for Science"

Figure 54. Two "Ride for Science" participants

Figure 55. Many volunteers assisted with the "Ride for Science" events

Figure 56. Many volunteers participated in the "Ride for Science" events


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Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101