Traffic Management
36. Diverters (Diagonal, Star, Forced Turn and Truncated)

A diverter is an island built diagonally across a residential street intersection which prevents certain through and/or turning movements. Diverters affect people living in the neighborhood more than anyone else. Therefore, diverters should be considered when less restrictive measures are not appropriate.

A diagonal diverter breaks up cut through movements and forces right or left turns in certain directions. A star diverter consists of a star-shaped island placed at the intersection which forces right turns from each approach. A truncated diagonal diverter is a diverter with one end open to allow additional turning movements. Other types of island diverters can be placed on one or more approach legs to prevent through and left turn movements and force vehicles to turn right.

As with other traffic management tools, diagonal diverters must be used in conjunction with other traffic management tools within the neighborhood street network. Any of these diverters can be designed for bicycle and pedestrian access.


  • Discourage traffic from cutting through a neighborhood.
  • Part of a bicycle boulevard system.


  • Impacts residents more than through traffic.
  • Consider less restrictive measures first.
  • Evaluate traffic patterns to determine whether other streets would be adversely affected.
  • Design diverters to allow bicycle and emergency vehicle access. If this cannot be done and the street is a major bicycle corridor, a diverter should not be used.
  • Diverters generally do not effectively address midblock speeding problems.
  • Diagonal diverters may be used in conjunction with other traffic management tools and are most effective when applied to the entire neighborhood street network.
  • Diverters should have strong neighborhood support.
  • Consideration should be made of diverters effect on service vehicles

Estimated costs

$15,00-$45,000 each, depending on the type of diverter. Diagonal Diverter Star Diverter Truncated Diverter Forced Turn Diverter