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The  report to which this is a response

Comments on Concord Avenue bike lane

The consultant  makes some very good suggestions, in particular, for signage and for tapering the right edge of the travel lane toward the right curb and/or installing left-turn pockets in the median so left-turning vehicles do not block through traffic. I also agree with him that the present bike lane narrows the travel lane excessively at some locations. The heavy wear on the lane stripe at the left side of the bike lane confirms this observation.

But the narrowness of the travel lane reflects another problem described on the previous page: there is not quite enough room for a bike lane. The Concord Avenue roadways are just a bit too narrow for a standard-width bike lane to be out of the range of opening car doors and for the travel lane also to be wide enough. Unless there is extremely heavy and fast motor traffic -- not the case on Concord Avenue -- bicyclists can easily merge left to overtake other bicyclists, making use of the travel lane width which is only intermittently occupied by motor vehicles. Also, bicyclists' preferred position on the roadway depends on whether or not parked cars are present. If there is a parked car, bicyclists check behind them for traffic, and move somewhat to the left to avoid the hazard of opening car doors.

A bike lane encourages bicyclists to overtake on the right and motorists to turn right from the left lane -- behavior which I have observed in the existing bike lane on Concord Avenue. Dashing the lane stripes can somewhat reduce these problems, but motorists still often think of a bike lane as a "sidewalk in the street" and keep left of it before turning. It is hard for motorists to think of a bike lane as a "real" lane, as it is too narrow for their vehicles. These problems occur wherever there are cross streets and driveways, and do not occur, for example, on bridges where there is no cross traffic.

For these reasons, I think that the bike lane with a stripe on either side delineating a special channel for bicyclists creates more problems than it solves. I suggest a single guide stripe similar to what Cambridge has implemented on much of Broadway, to delineate the right edge of the 11 foot travel lane recommended by the consultant. In addition, marked parking stalls would serve to indicate the parking lane clearly. "Share the Road" and lane use signs as recommended by the consultant are appropriate. The lane stripe should be tapered and dashed before the Stone Bridge underpass, to encourage through-traveling bicyclists to merge left and right turning motorists to merge right before reaching the underpass. Merging before turning is much safer, and is what the traffic law requires (MGL Chapter 90, section 14).

The consultant also suggests the use of neckdowns or bulbouts to prevent motor vehicle travel in the parking lane. They would certainly be successful in accomplishing that goal, but this suggestion is somewhat at odds with the recommendation to widen the travel lane at intersections. Certainly, the tapering and the neckdowns would have to be at different locations. Pedestrian crossings would then preferably be at the locations of the neckdowns.

All in all, I think that Concord Avenue in Belmont is an easy place to ride, because there is only one travel lane in each direction, and there is generally adequate width for lane sharing. But there is not quite enough room for a bike lane, and the bike lane that has been installed also has problems at intersections.