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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

Report
This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-HRT-05-112
 Date: July 2006

Lesson 14: Shared Roadways

This photograph shows two bicyclists riding single file in a wide curb lane. Vehicles are passing the bicyclists in the same lane but are not crossing the road centerline.

(This picture shows bicyclists not wearing helmets. FHWA strongly recommends that all bicyclists wear helmets.)

Lesson Outline

  • Shared roadways:
    – Pavement markings.
    – Wide curb lanes.
    – Paved shoulders.
    – Signed routes.
    – Bicycle boulevards.
  • Design considerations:
    – Rumble strips.
    – Drainage grates.
    – Railroad crossings.
  • Avoid!!
    – Sidewalk bikeways.
    – Raised curb dividers.

Shared Roadways

  • Nearly all roads (except where bicycling is prohibited):

    – Existing road.
    – Wide curb lanes.
    – Paved shoulder.

  • Lower speeds and traffic volumes.

Shared roadways include most existing roads and streets. This illustration shows an elevation view of a shared roadway with no pavement markings. In the sketch, two bicyclists in opposing directions are sharing the roadway with a motor vehicle.
* No pavment marking are required for shared roadways

Wide Curb Lanes

  • Provide where inadequate width exists for bike lane or shoulder.
  • 4.2–4.5 meters (m) (14–15 feet (ft)).
  • Not greater than 4.5 m (15 ft)—cars use as two lanes.

This illustration shows an elevation view of a wide curb lane next to an inside travel lane. The dimension of the inside travel lane is 3.6 m (12 ft), whereas the wide curb lane is 4.2 m (14 ft) of usable lane width. In the sketch, no pavement marking separates a bicyclist from a motor vehicle in the wide curb lane.

Shared Lane Pavement Markings

  • Indicate possible presence of bicyclists to motorists.
  • Improve bicyclist positioning near parked vehicles and other obstacles.
Various pavement markings for shared roadways and wide curb lanes.   Various pavement markings for shared roadways and wide curb lanes.   Various pavement markings for shared roadways and wide curb lanes.   Various pavement markings for shared roadways and wide curb lanes.

Shoulders and Shoulder Bikeways

  • Many other benefits besides bicycling.
  • Min. 1.2 m (4 ft).
  • Greater width for:

    – Roadside barriers.
    – High traffic volumes.
    – High traffic speeds.
    – Steep grades.

This illustration shows an elevation view of dimensions for paved shoulder bikeways. In the sketch, the following road elements have these dimensions: shoulder of 1.2 m (4 ft) minimum, 2 opposing vehicle travel lanes of 3.6 m (12 ft) each, and another shoulder in the opposite direction of 1.2 m (4 ft) minimum. An explanatory note indicates that a minimum shoulder width of 1.5 m (5 ft) is required from face of guardrail, curb, or other roadside barrier.

Designated Bike Routes

  • Considerations:

    – Route continuity.
    – Bicyclist and vehicle demand.
    – Adjusted traffic control devices.
    – Removed or restricted parking.
    – Smooth pavement surface.
    – Sufficient street width.

The top picture shows a bicycle symbol with the text 'BIKE ROUTE' below.

The bottom picture shows a bicycle symbol with a large number '4' below.

Source: http://members.aol.com/rcmoeur/

Bicycle Boulevards

  • Direct, continuous route.
  • Cross-traffic stops.
  • Vehicle traffic diverted.
  • Traffic calming used.
  • Ample signing.
  • Bicyclists protected at crossings.

This picture shows a bicyclist and pedestrian traveling along a bicycle boulevard. At the intersection, motor vehicle traffic is not permitted to travel straight across the intersection. Instead, motor vehicle traffic is forced to turn right.

(This picture shows a bicyclist not wearing a helmet. FHWA strongly recommends that all bicyclists wear helmets

Rumble Strips

  • Provided to alert motorists, but hazardous to bicyclists.
  • Min. 4 ft of usable shoulder width required.
  • Periodic gaps may be provided.

This picture shows a bike lane which has rumble strips along the left edge. Accompanying text says 'AVOID THIS! (rumble strips in bike lane)'.

Avoid This! (rumble strips in bike lane)

Drainage Grates

View Alternate Text

View Alternate Text

Railroad Crossings

View Alternate Text

View Alternate Text

Treatments to Avoid

  • Sidewalk bikeways:
    – Conflict at driveways/intersections.
    – Conflict with pedestrians.
    – Lead to confusion about right-of-way.
  • Raised concrete curbs (or other barriers) separating motor vehicles from bicycles.

Lesson Summary

  • There are many ways to allow motor vehicles and bicycles to share the same roadway.
  • Use of specific design elements creates a shared roadway that is bicycle–friendly.

 

FHWA-HRT-05-112

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