Bicycle Safety Guide and Countermeasure Selection System
Example of bicycle lane treatment at a right turn only lane. Illustration from Manual on Uniform Traffic Control Devices
A large percentage of crashes and conflicts between bicyclists and motor vehicles occur at intersections or other junctions such as driveways. Intersection pavement markings are one method of improving the awareness and visibility of bicyclists at these locations.
At locations with a bike lane approaching the intersection, the bike lane should continue through the intersection into a receiving bike lane on the far side. If a vehicle right-turn-only lane is introduced at this location, the correct placement of the bike lane is to the left side of the turn-lane. In some cases, particularly with bike lane retrofits, there is not enough room for a right-turn-only lane and a bike lane. In this condition, guidance should be given to the street users on where to expect bicyclists through the placement of shared-lane markings.
Sometimes dashed lines are used to indicate the proper path for the bicycle in a complex intersection. Colored pavement (green) may also be used for this purpose, as well as to indicate the weaving area for bicycles and motor vehicles when right-turning motor vehicles cross the path of bicycles in a bike lane. The intent is to increase awareness and safe behaviors by both cyclists and motorists and yielding behaviors by right- and left-turning motorists.
Other kinds of markings are available for use at intersections. An experimental bike box has gained popularity in the United States and may also be known as the advance stop bar. The box is an extension to a bike lane at the head of the intersection that is provided to improve the visibility of bicyclists and assist with their turning movements. The box allows bicyclists to get to the head of the traffic queue on a red traffic signal indication and then proceed first when the traffic signal changes to green. Such a movement is beneficial to bicyclists at the onset of the green phase and reduces conflicts when, for example, there are many right-turning motor vehicles next to a right-side bike lane. The bike box necessitates the installation of right-turn-on-red prohibition, which may reduce the capacity of the signal.
Being in the box, and thus at the front of the traffic queue, tends to make bicyclists more visible to motorists. Recessed stop lines operate similarly. These treatments should only be considered where there are a considerable number of daily bicycle commuters. Multilane streets with high traffic volume should be carefully evaluated to be sure the treatment would be safe.
Similar to the bike box, a two-stage turn queue box could be installed to assist bicyclists in making a left-turn across multiple lanes. This designated area is designed for bicyclists to continue through an intersection and then queue in front of cross-traffic to complete the left-turn.
Intersection markings cognizant of nonmotorized traffic create on-street travel facilities and separated space for bicyclists. They also serve to increase awareness and safe behaviors by both cyclists and motorists.
Costs will vary due to the type of paint used and the size of the symbol, as well as whether the symbol is added at the same time as other road treatments.
Painting a bicycle box will cost approximately $11.50 per square foot. Striping combines a number of related costs, such as: contraflow lanes, broken/solid white or yellow stripe, bicycle lanes, and bikeway centerlines. It also combines the wide assortment of widths and materials used for striping.
Authors and Acknowledgements