Cambridge Civic Journal Forum

April 27, 2010

New author, topic: bicycling; Concord Avenue

Hello, I’m John Allen, and I thank Bob Winters for welcoming me as an author on this blog.

My topic is bicycling. I am an active bicyclist; I ride both for transportation and for recreation. I lived in Cambridge from 1971 through 1979, and I have lived in the Boston area ever since. I have been active in bicycling advocacy since the founding of the Boston Area Bicycle Coalition in the late 1970s. I was a founding member of the Cambridge Bicycle Committee in the early 1990s. Over the years, I have paid a lot of attention to bicycling developments in Cambridge.

My opinions about the Cambridge bicycle program may confound your expectations, unless you have been reading my writings on other Web sites. While there are many good things that Cambridge has done, there are others which I find to have serious flaws. My work takes me to cities all around the USA and abroad, so I have had many opportunities to compare bicycle accommodations. There are cities I could hold up as examples — San Francisco, Albuquerque, Madison. In my opinion, Cambridge is not one of the more shining examples.

I will be posting later about developments over the years, but my present concern is with a construction project which has now started on Concord Avenue between Alewife Brook Parkway and Blanchard Road. Details of my concerns are explained on my own blog.

The City's before-and-after cross-section diagram of the Concord Avenue project

I have several general areas of concern:

  • The plan is to narrow the roadway, replacing the present bike lanes — whose installation I applauded — with sidewalk-level bikeways. The north-side (westbound) bikeway, like the present bike lane, will cross 7 streets and 24 driveways into an industrial area — so there will be very many turning and crossing movements. Most car-bike collisions involve turning and crossing movements. I only consider the westbound bike lane suitable for bicyclists who know how to avoid the conflicts. The raised bikeway will not resolve these conflicts, but it will create a false expectation of safety for child and novice bicyclists.
  • The bikeway is to slant down to street level at each of the streets and driveways, but only where it reaches one — not before, so there is no way for either bicyclists or motorists to negotiate lane position.  The presumption is that westbound motorists will always look back to the right and yield to bicyclists overtaking on their right, and that left-turning eastbound motorists will yield to bicyclists — who can be entirely hidden behind westbound vehicles. The so-called “right hook” and “left cross” collisions are already the two most common types of fatal car-bike collisions in the Boston area. The proposed design offers a wealth of opportunities for these collisions to occur.
  • Bikeways behind 6-inch-high curbs at sidewalk level make it inconvenient and unsafe for bicyclists to cross Concord Avenue — and in particular, to reach the eastbound bikeway from most of the streets and driveways on the north side. In this way, the design encourages wrong-way bicycling — which is much more hazardous than right-way bicycling, because the wrong-way bicyclists are where motorists do not expect them and where they are in conflict with right-way bicyclists.
  • The high curbs also pose the risk of bicyclists’ toppling into the street.
  • The present bike lanes drain and are plowed along with the rest of the street. The proposed bikeways, just behind the curbs, are where gutter splash will target bicyclists and where snow will be plowed from the street. The City claims that it will plow the bikeways, but I don’t expect that they will be cleared anywhere near as soon or as well as the roadway.
  • Creating a separate, narrow bikeway can not account for changes in the traffic mix, some of which are already underway.  Cargo tricycles, bicycle trailers and pedicabs will block the bikeway; mopeds aren’t allowed; electrically-assisted bicycles are faster than others and more likely to get into trouble on the bikeways, but slower than motor vehicles. Who knows what else the future will bring?
  • The turning and crossing conflicts between motorists and bicyclists will increase congestion of motor traffic on Concord Avenue, and particularly in the single westbound travel lane.
  • The south side of Concord Avenue is adjacent to Fresh Pond Reservation and has only a single driveway crossing in the project area — at a signalized intersection.  There is already a path extending part of the way along the south side of Concord Avenue; there is a sidewalk the entire way, and many bicyclists already use these westbound to avoid crossing all the streets and driveways. A  bikeway on the south side properly designed for two-way travel would accommodate child and novice cyclists safely and comfortably, and avoid creating congestion.
  • The project does not conform to the specifications in the award-winning Massachusetts Project Development And Design Guide, widely regarded as the best in the nation. I understand that the project is funded by the Commonwealth. Nonetheless, the project somehow slipped through the review process. Though City officials claim otherwise, neither does the project correspond to good European practice.  It is a weak imitation of European practice.

The City makes the indirect claim of “safety in numbers” for this project. That is, when there are more bicyclists, motorists become more attentive and better at avoiding collisions. I agree that this happens, but I don’t agree with it as the justification for an all-around poor design. When bicyclists are placed where motorists can’t see them, safety is only achieved when everyone slows way down — same way as when pulling out of a blind driveway. This type of situation leads to frustration and animosity, because transportation is about people wanting to go places — both bicyclists and motorists. And the planned westbound bikeway is so inherently hazardous that I don’t expect either safety or numbers!

My recommendations? Leave the bike lanes as they are. Install a two-way bikeway on the south side, if that is practical. Provide a couple more signalized crossings, with signals timed so traffic flows smoothly and/or median refuge islands. Also look to other east-west through routes. One is already rideable, and funded for improvement, the Fitchburg Cutoff path between Alewife Station and Blanchard Road, north of the commuter rail tracks.  The City’s Concord-Alewife Plan describes another route to be developed south of the tracks.

Bicycling advocates learned of the Concord Avenue project rather late. Construction has already begun, and I’m not very hopeful that the project can be changed. But whether or not it is changed, I consider public discussion and awareness important. I welcome comments. Thank you for your attention!


  1. John:
    Good summary. You have elaborated well on what I just knew was a really bad design. Thanks for the information.

    Comment by Ed Kross — April 27, 2010 @ 8:18 pm

  2. A photo or two of what you mean would be useful; I assume you’re talking about the same ‘baked into the sidewalk’ bike paths that I see on (I think) Vassar Street) as it runs along MIT. I do like the path structure in that location, but I can see your point that in other, more active neighborhoods (that is, not academic buildings and warehouses), bikes are better based in the street with cars and motor traffic.

    Comment by Matt — April 28, 2010 @ 7:02 am

  3. Response to Matt: Thanks for your comment. Unfortunately, there are no photos of the planned configuration because it doesn’t exist yet. It is rather different from the one on Vassar Street, which is a few feet back from the curb and which is troublesome enough but this is worse. I will post the City’s cross-section diagram, per your request, but I want to avoid taking up too much space on Robert’s blog. To see many more photos and drawings, please go to the post on my own blog, ; I also recommend Paul Schimek’s post at .

    Comment by jsallen — April 28, 2010 @ 8:38 am

  4. These are concerns and has been explained well. Interesting to see how far you wish to take this

    Comment by Jim Nariel — May 5, 2010 @ 5:10 pm

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