Road Design
11. Roadway Narrowing

Roadway narrowing can be achieved in several different ways:

1) Lane widths can be reduced (to 9, 10, or 11 feet) and excess asphalt striped with a bicycle lane or paved shoulders;

 2) Travel lanes can be removed (see 12); or,

3) the street can be physically narrowed by extending sidewalks, landscaped areas, or by adding on-street parking within the former curb lines.

This can reduce vehicle speeds along a roadway section and enhance movement and safety for pedestrians. Bicycle travel will also be enhanced and bicyclist safety improved when bicycle lanes are added.

 

Purpose:

  • Multiple benefits in terms of reducing speeds, increasing safety, and redistributing space to other users.

Considerations:

  • Bicyclists must be safely accommodated. Bike lanes or wide curb lanes are needed if motor vehicle volumes and/or speeds are high.
  • Road narrowing must consider school bus and emergency service access, and truck volumes.
  • Evaluate if narrowing may encourage traffic to divert to other local streets in the neighborhood.

Estimated cost

Adding striped shoulders or on-street bike lanes can cost as little as $1000 per mile if the old paint does not need to be changed. The cost for restriping a mile of street to bike lanes or reducing the number of lanes to add on-street parking is $5,000$10,000 depending on the number of old lane lines to be removed. Constructing a raised median or widening a sidewalk can cost $100,000 or more per mile.