Characteristics of Emerging Road and Trail Users and Their Safety

  • Published: US Department of Transportation, Federal Highway Administration (FHWA)
  • Authors: US Department of Transportation, Federal Highway Administration (FHWA)
  • Date Added: 13 Jun 2013
  • Last Update: 13 Jun 2013
  • Format: pdf


To better understand the physical dimensions and operational characteristics of an increasingly diverse group of non-motorised trail and roadway 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. A total of 811 participants were observed at the three events.

Key Findings:

  • With the increasing variety of emerging users comes the question of whether the US are designing and building suitable facilities. Many jurisdictions throughout the United States have adopted the American Association of State Highway and Transportation Officials (AASHTO) Guide to the Development of Bicycle Facilities as a standard for shared use trail design and other facilities used by non-motorised travellers.

  • The results confirmed the great diversity in the operating characteristics of various road and trail user types including:

    • Sweep Width - The 85th percentile inline skater had a 1.5 metre sweep width, wider than the AASHTO recommended width for bike lanes.

    • Design Speed - Recumbent cyclists had the highest observed 85th percentile speeds of 18 mph, less than AASHTO’s minimum design speed.

    • Horizontal Alignment - Most users did not reduce their speeds for turning radii greater than 16 m.

    • Stopping Sight Distance - A recumbent cyclist in the 85th percentile requires a stopping sight distance of 32.7m 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, 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 (18.3m wide) junction.

    • Characteristics of electric personal transporter devices (for example Segway) Users - Many characteristics of electric personal transporter devices 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.


Design, User types, New technologies.


Although from the US, this research could potentially be relevant to the UK.