Cambridge Civic Journal Forum

October 6, 2013

Cambridge at cross purposes about traffic

Readers of the newsletter of the Belmont Citizens Forum will find much news there about neighboring North Cambridge. Editor Meg Muckenhoupt’s lead story in the September-October 2013 issue is about major, new housing developments planned for the part of Cambridge west of Alewife Brook Parkway and north of Fresh Pond Park. The article expresses concerns with traffic which is already approaching gridlock and affecting access to the Alewife T station.

Quoting from the story:

The decision document issued by Cambridge’s Planning Board for the 398-unit 160 Cambridgepark Drive, which is predicted to cause 1,324 new trips, states, “The project is expected to have minimal impact on traffic and will not cause congestion, hazard, or substantial change to the established neighborhood character.” Ominously, the decision continues: “It is also noted that the traffic generated by the project is anticipated to be less than that associated with the office/research and development project on 150, 180 and 180R Cambridgepark Drive for which entitlements currently exist under a previously granted special permit.” In short, if the city of Cambridge accepted a potential increase in traffic for a special permit in the past, the city should accept that increase in traffic for all future permits—no matter how much the population has increased in the meantime.

[…]

Concord Avenue and the Alewife Brook Parkway rotary won’t escape traffic woes. Cambridge’s 2005 Concord Alewife Plan included a “critical movement analysis” of the area. Critical movements are conflicting traffic movements. They are the times when vehicles block each other from moving, such as when a car turns left and crosses a lane of oncoming traffic. The Concord Alewife Plan reports that for the area roughly bounded by the Route 2/Route 16 intersection, the Alewife Brook Parkway, and Concord Avenue, service starts to deteriorate when a roadway reaches the “critical sum” of 1,500 vehicles per hour, or 1,800 vehicles per hour for rotaries. Below those numbers, and most motorists can get through an intersection in two or fewer light cycles. Above those thresholds, you’ll wait at that light a long time. As of 2005, the Concord/Route 2 rotary was already operating at 1,880 critical interactions—80 above the threshold—with a total traffic volume of 4,300 trips per day, while Concord Avenue at Blanchard Road had already reached 1,400 “critical sums” per hour, with 2,460 trips per day.

The report also predicted vehicle trips per day for 2024 for the area after Cambridge’s rezoning (which Cambridge enacted in June 2006.) The permitted 70 Fawcett Street development, which will be located between these two intersections, by itself promises to add enough vehicle trips to reach the predicted 2024 buildout trip level by 2014—and there’s plenty more space for apartments and garages alongside between the Concord Avenue rotary and Blanchard Road.

Also:

Of course, some of these buildings’ residents will take the T to work—if they can fit on the T…The Red Line is already “congested” and running at capacity, according to a June 2012 study by the Urban Land Institute titled Hub and Spoke: Core Transit Congestion and the Future of Transit and Development in Greater Boston.

So, Cambridge publishes a plan for the Alewife area which reports that traffic congestion is already a problem, but then it permits several large housing developments which will worsen it. The Belmont Citizens Forum article does report that design study has been funded for a new bridge over the commuter rail tracks west of Alewife Station, connecting it with Concord Avenue. That will relieve some congestion near the Alewife Brook Parkway/Concord Avenue rotary but will have little effect elsewhere. And this is still only a design study.

As a bicycling advocate and repeated critic of Cambridge’s treatment on Concord Avenue — see summary of my comments here — I have found another major inconsistency with the 2005 Concord-Alewife Plan: the recent reconstruction of Concord Avenue so as to maximize the number of conflicts between bicyclists and motorists. The new traffic signal just west of the Concord Avenue/Alewife Brook Parkway rotary backs up traffic into the rotary whenever a bicyclist or pedestrian actuates the signal to cross. The westbound sidewalk bikeway installed on the north side of Concord Avenue crosses a driveway or street on average once every 100 feet, requiring motorists to stop in the only westbound travel lane, blocking traffic, to yield to bicyclists overtaking on their right. Buses traveling both ways on Concord Avenue must stop in the travel lane, where their doors open directly into the bikeway. The conflicting turn movements between motorists and bicyclists, and bus passengers discharged onto the the bikeway, pose serious safety concerns too.

In previous posts on this blog and elsewhere, I recommended a two-way bikeway on the south side of Concord Avenue next to Fresh Pond Park, where there is only one signalized intersection, and maintenance of the previous roadway width and bike lanes.

The 2005 Concord-Alewife Plan contains no mention of the Concord Avenue bikeway — see recommendations for Concord Avenue on page 80 of the report. The plan therefore does not account for the congestion caused by the bikeway, on which construction began only 4 years later.

The overall impression I get is that Cambridge’s planning is disorganized, but also, Cambridge’s bicycle planning occurs in a fantasyland where the well-known conflict situations which cause crashes are greeted with a claim that the goal is to make bicycling more attractive, then, poof, when there are more bicyclists, by magic, bicycling will become safer. I call this the “Pied Piper” approach to bicycle planning. Well, actually, Cambridge is reporting a steady level of bicycle crashes in spite of an increasing volume of bicycle traffic. Some decrease in risk with increasing volume occurs with any mode of transportation as its users gain longer experience. The issue I have is with using this as an excuse for wishful thinking and crap design, and writing off the victims of preventable crashes as expendable. Cambridge has had some gruesome preventable crashes, and has intersections with the highest volumes of bicycle crashes anywhere in Massachusetts.

Another overall impression which I can’t shake is that Cambridge is very selective about reducing traffic congestion. The Concord Avenue project; the residential developments planned for the Alewife area; the Western Avenue roadway narrowing and sidewalk bikeway; and the proposed bikeways along Binney Street increase congestion at the portals to the city. It all strikes me as rather desperate and underhanded way to decrease congestion in the core of the city, but there you have it, as it appears to me.

[Added paragraphs, October 7, 7:40 AM] Residential development close to the urban core is certainly preferable to sprawling suburbs to minimize environmental impacts and traffic congestion, but resolving the traffic problems in the Alewife area would require major investments to increase Red Line and bus service, and disincentives (read: high cost) for single-occupant motor vehicle travel. The public resists all of these. If there is a logic to the City’s approach to these challenges, it is to break down resistance by making the problems so pressing that the pain becomes intolerable.

Bicycling and walking can make some contribution, but the plans for the new housing developments describe it as small. Quoting again:

To be fair, the developers of these various projects are attempting to make car-free commuting more attractive to their residents. Several of these buildings have extensive bicycle-parking facilities, including the Faces site and 160 Cambridgepark Drive. But the city of Cambridge doesn’t anticipate that those bicycles will get much use. For 398-unit 160 Cambridgepark Drive, for example, the city estimates the residents will make 1,324 daily car trips, and 202 pedestrian trips, but just 98 journeys by bike.

Most of the traffic in the area in any case is to or from more distant locations, or is passing through. Bicycling and walking may serve as feeder modes for these longer trips but don’t compete well with motorized modes to cover the distance.

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