photo shows a triangular island separating one lane for right-turning traffic from the remainder of the intersection. The lane has a painted crosswalk from the island to the curb. A man is waiting at the crosswalk to cross the lane from the island to the curb. A row of cars is in the lane in front of him, with the first car approaching the crosswalk. On the island, on top of a pole beside the man, is a walk signal for crossing the main street behind him.
SEPARATE RIGHT-TURNING LANES



Separate or "channelized" right-turning lanes are separated from the rest of the intersection by painted lines or raised barriers, usually in the shape of a triangular island. Traffic in these separate right-turning lanes comes from one street (the "upstream" street), turns right and then has to yield to or merge into traffic on the perpendicular street (the "downstream" street).


There is usually a pedestrian crosswalk where drivers are supposed to yield to pedestrians, but they do not always reliably stop (see experiments at separate right-turning lanes in Maryland and California). If the crosswalk is located where traffic has to yield to vehicles on the downstream street, the traffic often is going more slowly and is therefore more likely to stop. However, drivers may not see pedestrians to their right because they are looking only to their left for vehicles.


There are several variations in the design of separate right-turning lanes:

  • It may have an acceleration or a deceleration lane or both;
  • The radius of the turn can vary;
  • There may be a signal specifically for traffic in the separate right-turning lane.


    drawing shows a corner; one street shows two lanes going east, the other street shows two lanes going south. A right-turning lane cuts through the corner from the east-bound street to the south-bound street. One car in the east-bound lane is going straight, another car from that same lane is turning into the separate right-turning lane. That car will have to stop and wait for traffic to clear before it can enter the south-bound street.

    Acceleration and deceleration lanes:

    In the drawing to the left, there is no acceleration or deceleration lane. As a result, traffic approaching the intersection can go straight or turn right when it reaches the right-turn lane. Traffic coming out of the right-turn lane must yield to traffic before entering the other street.

    The drawings below have acceleration and/or deceleration lanes:

  • DECELERATION LANE: The first drawing below shows a deceleration lane for approaching traffic -- traffic in that lane cannot go straight, it must enter the separate right-turning lane;

  • ACCELERATION LANE: The second drawing shows an acceleration lane -- traffic coming out of the separate right-turning lane can enter the other street without yielding or merging into its traffic;

  • DECELERATION AND ACCELERATION LANES: The last drawing shows a right-turning lane with both an acceleration and a deceleration lane.

    Deceleration lane: The drawing shows a car in the east-bound lane -- his lane is blocked by the island, and he must turn right into the separate right-turning lane. Acceleration lane: The drawing shows a car in the separate right-turning lane entering a new lane in the south-bound street. Drawing shows a separate right-turning lane with an acceleration and a deceleration lane.


    Drawing shows a street going east-west, and an intersecting street going southeast. The southeast corner is about a 45-degree angle, and the southwest corner is about 135 degrees. Each corner has a separate right-turning lane.

    Radius of the turning lane:     The radius of the turning lane can be small (SE corner in drawing to the left) or extremely wide (SW corner).

    Because of these variations, separate right-turning lanes present a wide range of difficulty for pedestrians to cross.

    For example, those which have a deceleration lane, a wide radius, and an acceleration lane with no traffic signal are the most difficult to cross, because the deceleration lane, combined with the wide radius, means that the traffic does not have to slow down to approach the intersection, and it does not even have to slow down to yield to perpendicular traffic if there is an acceleration lane. The SW corner of the drawing above has each of these features except the acceleration lane -- click here for an analysis of the risks of crossing there.

    On the other hand, separate right-tuning lanes which have a tight radius and no acceleration or deceleration lanes are much easier to cross. The presence of an accessible pedestrian-actuated signal to stop the traffic can also make it easier.

    Strategies for crossing:
    NOTE: Click here for a forum discussion of ideas for crossing separate right-turning lanes.

    If there is no signal or stop sign at the crosswalk, it is an uncontrolled crossing. Strategies for blind people to cross at uncontrolled crossings include:

  • Cross when there is a gap that is long enough (this can be done only when it is possible to determine if vehicles are approaching – see "Situations of Uncertainty for Gap Judgment").

  • Get drivers to yield. If crossing more than one lane, there should be assurance that traffic in all lanes has yielded.

    As always, if it is not possible to determine when it is safe to cross, the level of risk must be considered (click here for an example). If the level of risk is not acceptable, alternatives should be considered.

    Inman, Vaughan. W., Davis, Gregory. W., and Sauerburger, Dona. (2005) Pedestrian Access to Roundabouts: Assessment of Motorist Yielding to Visually Impaired Pedestrians and Potential Treatments to Improve Access. Federal Highway Administration Report DTFH61–02–C–00064

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