Bicycle Safety Guide and Countermeasure Selection System

 

Landscaping causing site distance challenges. http://www.pedbikeimages.org/ - Libby Thomas


 

 

 

Sight Distance Improvements

Adequate sight distance is vital for safe bicycling. Bicyclists need to see the movements of motor vehicles, and vice versa. Intersections are often areas where a number of sight distance problems occur. For example, on-street parking of motor vehicles can restrict the view. Removing a parking space from the roadway can help improve sightlines through an intersection. Removing a parking space on the approach into an intersection may help bicyclists to safely cross the street by providing them with a clearer view of oncoming vehicles. However, it may also be important to provide physical roadway measures, such as curb extensions, to prevent motorists from parking near the intersection. If curb extensions are out of the budget range, vertical delineators can work to prevent motorists from parking vehicles too close to a crosswalk.

Improper placement of signs as well as landscaping that is either too low or too tall can also impede the line of sight. Skewed intersections, where cross streets are greater or less than 90 degrees, can make it difficult to see other vehicles, as well as increase the exposure of bicyclists (or pedestrians) crossing the street. Problems similar to those listed above also often occur where driveways intersect with streets.

Purpose

Keep streets and intersections clear and unimpeded improves line of sight for all modes of traffic. This increases awareness and safe behaviors by both cyclists and motorists, increases their reaction times and decreases stopping distances.

Considerations

  • Determine whether on-street parking is necessary.
  • Determine the most appropriate kind of parking if necessary.
  • Provide appropriate signs at street intersections and problem driveways.
  • Provide the appropriate kinds of trees, shrubbery, and flora.
  • Place street furniture so sight distance is not reduced.
  • Determine if skewed intersections should be realigned.

Estimated Cost

Costs will vary depending on the treatment. Re-striping may be all that is necessary to eliminate unnecessary parking. The cost of sign removal or relocation is dependent on the size of the signing. The same would also be true for removal of trees, shrubbery, and other flora.

References

To view references for this countermeasure group click here.

Case Studies

Portland, Oregon