Traffic Calming Measures - Closure

  • closures are typically applied only after other measures have failed or been determined to be inappropriate
  • for all types of closures, provisions are available to make diverters passable for pedestrians and bicyclists
  • often used in sets to make travel through neighborhoods more circuitous - typically staggered internally in a neighborhood, which leaves through movement possible but less attractive than alternative (external) routes
  • closures have been used as a crime prevention tool
Full-street Closure

Diagonal diverters are barriers placed diagonally across an intersection, blocking through movement; they are sometimes called full diverters or diagonal road closures

Diagonal Diverter

Half closures are barriers that block travel in one direction for a short distance on otherwise two-way streets; they are sometimes called partial closures, entrance barriers, or one-way closures (when two half-closures are placed across from one another at an intersection, the result is a semi-diverter)

Half Closure

Full-street closures are barriers placed across a street to completely close the street to through-traffic, usually leaving only sidewalks open; they are sometimes called cul-de-sacs or dead-ends

Full-street Closure

Median barriers are raised islands in the centerline of a street and continuing through an intersection that block the left turn movement from all intersection approaches and the through movement at the cross street

Median Barrier

Design/Installation Issues:

  • there may be legal issues associated with closing a public street
  • can be placed at an intersection or midblock
  • barriers may consist of landscaped islands, walls, gates, side-by-side bollards, or any other obstruction that leave an opening smaller than the width of a passenger car

Potential Impacts:

  • concern over effects on emergency response, street network connectivity and capacity, and parallel local streets that carry diverted traffic
  • may divert significant traffic volumes
  • no significant effect on vehicle speeds beyond the closed block

Emergency Response Issues:

  • half closures allow a higher degree of emergency vehicle access than full closures or diagonal diverters
  • all three types of closures can be designed to allow emergency vehicle access

 Typical Cost:

  • costs range between $2,000 for a simple half-closure and $35,000 for highly-landscaped diagonal diverter

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