"Bikes Allowed Use of Full Lane"--BU Bridge, Boston, MA

Posted by Mike Tremblay

The BU Bridge is located at the center of the BU campus, not far from the Boston University Central MBTA station. It starts from Commonwealth Avenue and spans Storrow Drive and the Charles River and allows access to Cambridge and Memorial Drive. The bridge seems to be undergoing renovation right now, as jersey barriers have been placed between the sidewalks and the street. The roadway, judging from 2007 Google Street View photos, was reduced from a 4-lane road to a 2-lane road in order to widen the sidewalks (see Google Image at the bottom of this post). The existing two-lane road has no shoulder or bike lane This alteration, presumably along with the efforts to make Cambridge as well as the Commonwealth Avenue area bike-friendly, probably caused signs to be installed and road markings painted indicating that bicyclists are allowed use of the full lane.

The intended use of the shared-use roadway is for cyclists to be allowed to use the full lane, as shown in the posted signs, and cars to drive behind them until it is safe to pass.

Possible design considerations of making the road a shared-use roadway:

• Link Cambridge and Commonwealth Avenue, both of which are attempting to be bike-friendly areas
• Keep cyclists off of sidewalks if possible, since there are a lot of pedestrians using the BU Bridge's sidewalk
• The roadway is not wide enough for bike lanes, so a shared-use lane designation is better than nothing at all

The signs and roadway markings may help cyclists feel more comfortable in the shared use lane, since cars know that the cyclists are allowed to be there. However, most of the cyclists observed using the BU Bridge did so using the sidewalk, and some rode on the street but uncomfortably close to the jersey barriers, as if to ride in an imaginary bike lane. Only a small portion (about 25%) of cyclists utilized the entire lane, as intended. It should be noted that I observed the bridge on the afternoon of the Boston Marathon, which may have affected the amount of traffic traveling to and from Commonwealth Avenue.

The shared-use lane was built so that bikes wouldn't try to squeeze against the side of the road or use the sidewalk to cross the BU Bridge, but this intention does not seem to be fulfilled except with more "vehicular" riders. The bridge is quite prohibitive space-wise, however, so there aren't a lot of other options. One option may be to have a bike lane (or an "undesignated lane" if there isn't 5' to spare) on one side and have the other side remain shared-use. Another option could be to paint shoulders on the sides of the road, which would keep cars hugging the centerline and would give cyclists room to ride along the side of the road. If the jersey barriers currently on-site are indeed temporary, the shared-use lane is probably sufficient.

Another improvement that could be made, unrelated to the BU bridge, is the MBTA crossing at Commonwealth Avenue. Cyclists that have to cross this median must deal with uneven surfaces, chipped asphalt, and MBTA tracks. The last thing we want is a cyclist to lose control of a bike on a subway crossing in the middle of a major street.