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These are types of enclosed roadways with access at both ends.

Design & Safety Issues to Consider:
  • Absence of bicycle facility on approaches should not prevent bicycle accommodation within the tunnel/underpass
  • Options include widening or eliminating existing sidewalks in tunnels
  • Sidewalks in tunnels may act as barriers to prevent vehicles getting too close to the side or for emergency use
  • Good lighting is important so that motorists can see and react to bicyclists
  • Consider personal safety in tunnels
  • Overhead clearance needs to be maintained throughout
  • Unexpected ice patches can form from overhead drips
  • Road hardware in tunnel pavement
  • can be less visible and cause problems
Review Checklist:
  • Provision of adequate width bike accommodations on both sides of roadway through tunnel
  • Adequate vertical clearance
  • Tunnel abutments clearly marked
  • Road hardware and obstacles


These are the intersections of a roadway or a path with a railway line or tram line.

Design & Safety Issues to Consider:
  • Railroad tracks that cross the route of a bike on an angle can cause steering difficulties for bicyclists
  • Angle of track should be at least 60 degrees or better so bicyclist can safely cross
  • Railroad crossing surfaces vary: concrete, rubber, asphalt, or timber
  • Concrete provides the smoothest and least slippery riding surface
  • Shared lane markings may be used to guide bicyclists to the best route and angle of crossing
Review Checklist:
  • Angle of railroad track relative to path or bike travel
  • Crossing surface and condition
  • Width and depth of flange opening
  • Signs and markings


These are structures erected over a depression or an obstruction such as water or a roadway.

Design & Safety Issues to Consider:
    • Bridges can be a significant barrier to bicycling due to lack of dedicated space
    • Bridges are often narrower than approach roads
    • Absence of bicycle facility on approach should not prevent bicycle accommodation on bridge
    • Sidewalks may be acceptable bicycle facility for long narrow bridge
    • Consideration should be given to shared-use path with concrete barrier on both sides of bridge
    • Where bridge is too narrow, it may be possible to add cantilever structure to accommodate bikes
Review Checklist:
  • Side rail heights: 42 inches min.
  • Side rail heights with higher bicycle speed: 48 inches
  • Full pavement width maintained
  • Provision of bike accommodations on both sides of roadway
  • Bridge deck surface and joints
  • Road hardware on bridge deck
  • Signs and markings

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