Device name(s): Curb Extensions/Bulb Outs/Neck Downs

Curb Extentions or Bulb Outs

Approximate Cost:$5000 – $15,000 per corner

Definition: Bulb outs, also referred to as curb extensions, narrow the roadway at the corners of an intersection by extending the curb into the parking lane or shoulder. Bulb outs narrow the width of the road which can reduce motorists’ speeds as they travel through the intersection, particularly when turning. These devices reduce the pedestrian crossing distance and improve motorists’ visibility of pedestrians. Bulb outs may be installed at an intersection or mid-block. Bulb outs placed mid-block are also known as Chokers. Curb pension without vertical horizontal deflection have been effective in reducing the 7% (from dirty 4.9 232.3 mi./h).

Fast Facts:

  • Can be used on Local Street- yes
  • Can be used on Collector- yes
  • Can be used on Arterial- yes
  • Reduces Speed- yes
  • Reduces Volume- no
  • Noise Impact- no
  • Restricts Access- no
  • Bicyclist Impact- possible
  • Transit Impact- yes
  • Parking Impact- possible
  • Emergency Response Impact- no


  • effective in reducing turning speeds
  • shortens pedestrian crossing distance
  • improves visibility of pedestrians
  • reduces vehicle speeds as motorists approach intersections
  • reduces crossing distance for pedestrians and bicyclists


  • increases regular maintenance
  • may affect larger vehicle turning radius
  • cannot be used on streets with established bike lanes, do not accommodate bicycle crossing at intersections
  • can eliminate some off street parking

Curb Extension or Bulb Out