BICYCLE FACILITY DESIGN REVIEW/ROUNDABOUT


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The modern roundabout is an increasingly popular type of intersection that usually operates with a yield traffic control at the entry points and gives priority to vehicles within the roundabout. Bicyclists can generally mix easily with low-speed traffic on single-lane roundabouts. On some multi-lane roundabouts, options such as providing a bicycle ramp exit to sidepaths should be considered to reduce potential conflicts. More than 40 roundabouts have been built recently in Virginia, and another 50 are in various stages of development.
Design Standards & Guidelines:
  • Urban roundabouts maximum entry speed: 20-30 mph
  • Bike lane termination prior to roundabout, distance from edge of circulatory road: 100 feet
  • Dash bike lanes prior to tapering into pedestrian crosswalk at roundabout: 50-100 feet
  • Bike lane taper rate prior to bicycle ramp access to path: 7:1

One of four roundabouts installed at Gilberts Corner, Loudoun County, Virginia

Design & Safety Issues to Consider:
  • Single-lane roundabouts can provide safety benefits for bicyclists when their needs are incorporated
  • High-speed multi-lane roundabouts require special design solutions for bicycles
  • Bike lanes are usually discontinued prior to the roundabout and are not striped on the roundabout as they would create turning conflicts at entrances and exits
  • Bicyclists are most vulnerable when circulating on the roundabout and entering traffic does not yield or when circulating traffic exits across the path of the bicyclist
  • Good visibility and yield enforcement are very important for the safety of bicyclists
  • Some bicyclists will choose to travel on the roundabout roadway while others may choose to exit immediately prior and use the pedestrian system to navigate the roundabout
  • Bicycle ramps can be provided to allow access to the path system at a roundabout but care must be taken to avoid potential confusion for pedestrians
 
Review Checklist:
  • No bike lanes on roundabout
  • Number of lanes on roundabout
  • Merging of bicyclists with roundabout traffic
  • Termination of bike lane prior to roundabout
  • Vehicle entry speed
  • Signs and striping
  • Visibility and sight distance



Recently installed traffic roundabout, Midlothian, Virginia

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Guide for Reviewing Public Road Design and Bicycling Accommodations for Virginia Bicycling Advocates