Prince George's County, MD



Forced Turn Islands
     

Forced turn islands are:

  • Volume control measures.
  • Formed by barrier islands that block certain movements on approaches to an intersection.
  • Good at reducing unwanted through traffic by altering specific movements at an intersection.
  • Also known as right turn islands.
  • Good for local residential applications.

 
   

Typical Design:

  • Designs can varie significantly depending on the installation location.
  • The Institute of Transportation Engineers has design recommendations.(2)

 
   

Placement Issues:

  • Best if used on residential streets at intersections with larger collector streets. This allows the larger street to accommodate the diverted traffic and helps to cut down on the number of individuals that might illegally circumnavigate the measure.
  • Emergency vehicle service is not greatly affected by forced turn islands since the emergency vehicle can circumnavigate the measure or the measure can be designed to be mountable.

 

 
   

Approximate Cost:

  • Installation costs for a forced turn island are about $3,000 and up depending on the size and design features.

 
   

Comments:

  • Should be installed only with strong community support since they restrict access for neighborhood residents.
  • Forced turn islands can be installed temporarily with low costs to test the effectiveness. The trial period should last 6-12 months.
  • When designing forced turn island, proper signage is necessary and considerable attention should be given to aesthetics.

 

 
   
Advantages
Disadvantages
  • Eliminates specific through traffic.
  • Can improve pedestrian safety.
  • Can improve the aesthetics of a neighborhood when landscaped tastefully.
  • Access is restricted for neighborhood residents.
  • Can shift cut through traffic problem elsewhere.
Home