Curb Extensions

A curb extension is a horizontal intrusion of the curb into the roadway, resulting in a narrower road section. Curb extensions increase pedestrian visibility for drivers and improve sight lines for pedestrians. As a result, pedestrians experience shorter crossing distances and drivers are required to slow down. Curb extensions can also create parking bays, narrowing the street and expanding the availability of on-street parking.

Application/Considerations/Outcomes

• Appropriate for local, collector, and urban arterial streets
• May interrupt bike lanes
• May reduce on-street parking
• May impact intersection operations through the reduction of lane provision
• Reduced turning radii may impact emergency service vehicles and larger vehicles turning at the intersections
• Potential damage to the curb during snow removal operations
• Increased snow removal costs and operation time
• Drainage system adjustments and utility relocations, such as utility poles and fire hydrants, may be required to accommodate roadway narrowing
• Adequate clear sight triangles should be maintained within the curb extension; obstructions such as vegetation overgrowth and landscaping should not limit the sight distance at intersections

Image sources: NACTO