Opinion guest column

Street maneuvers

Where MassDOT might fall short on bike safety

8500 longfellow proposed %283%29
A proposed plan for Longfellow Bridge, advocated for by the Boston Cyclists Union, would contain one lane for cars and a wide, protected bike lane.
Courtesy of Ari Ofsevit/Created with Streetmix under license CC BY-SA 4.0

Transportati­on affects everyone. Unless your thesis is due in a week, you’re probably going to go somewhere at least once per day. On such a pervasive subject, everyone has their own preferences, opinions, and horror stories. Today, we’re diving into the issue of bike safety, which is important to many Cambridge residents and MIT students. Biking is often the most convenient way to get around. Jumping between meetings across campus suddenly becomes a breeze, and you can leave for class five minutes in advance and still be on (MIT) time. What’s not to love?

Unfortunately, cycling in the city can sometimes be a harrowing experience. The Cambridge Police Department reports 160 crashes a year between bicycles and vehicles, and many more incidents go unreported. Cambridge Bicycle Safety, a local advocacy group, is crowd-sourcing stories of crashes and close-calls through the “scary moments project” to raise awareness of these continuing dangers that unfortunately fall too easily off the radar of the public and our elected officials. Drivers in lines of cars who are anxious to get to work amid traffic-clogged streets have little patience for bicyclists sharing the road. Taxis and ride-hailing drivers suddenly swerve in and out of traffic, and together with delivery trucks block unprotected bike lanes, forcing people on bikes into dangerous merging situations. Over 50 percent of MIT students are discouraged from biking around because of these dangers.

Efforts by organizations across the Boston area are pushing for changes to the street infrastructure, including on heavily-used roadways near MIT like Mass Ave, because bad design is at the heart of many such conflicts. Some changes are small, such as creating a curb cut and crosswalk which you may have seen this fall crossing Vassar Street. Others are larger, such as the Cambridge Bicycle Plan, which lays out a vision for a network of protected bicycle lanes. This week, we write about problems with bicycling on one of the largest projects in the state, the Longfellow Bridge.

If you don’t remember the pre-2013 Longfellow configuration (yes, it’s been under construction for five years), go out and take a look at the Mass Ave Bridge. The bike lane is just five feet wide, and the right half is taken up by sewer grates. Cars are temporarily freed from Boston’s gridlock and without much enforcement, many drivers attempt to win the Indianapolis 364.4 (± 1 ear), gunning across the bridge (speed limit: 30) at 40, 50 or even 60 mph. Cyclists can choose between hugging the “crash barrier” (that’s the technical term) or bumping elbows with a stream of Massachusetts drivers proudly attempting to break the sound barrier.

The Longfellow is worse. With the Red Line in the middle, there’s no opposing traffic to temper speeds: it feels like a highway and drivers treat it as such. Since it climbs a steep grade, cyclists — who, at rush hour, account for over one third of the traffic on the bridge according to 2017 data — travel at lower and more variable speeds, yet passing someone slower means merging into a traffic lane where a driver may be smoking along at 60.

The Longfellow has relatively little traffic, and the proposed solution is rather simple: a single lane of traffic for cars, a median, and a wide, comfortable bike lane which allows cyclists to safely pass each other. This is the plan for the outbound side of the bridge, but in 2012, MassDOT refused to allow this plan for inbound traffic. Their rationale was that since traffic backed up into Kendall Square, the backup would be twice as bad with a single lane. This logic is flawed for two reasons.

First, the potential for backup is less a factor based on the number of lanes on the bridge and more on the downstream congestion in Boston. If Cambridge Street backs up in Boston, it leads to congestion on the bridge. The second reason is the concept of induced demand. Traffic congestion has properties similar to a gas: it expands to fill its container. As the road capacity increases, so will the demand (and the traffic). However, for the past five years, we haven’t seen backups into Kendall Square even with a lane closed for construction. Some drivers have found other routes, some other modes, and others just haven’t made the trip. Perhaps some even switched to biking.

Given this track record, MassDOT should acquiesce: if one lane has worked since 2013, it can work in the future. The cycling community has even sweetened the deal: the double-wide bike lane provides an easy path for emergency vehicles to bypass congestion. It’s a lot easier for a cyclist to clear a lane than a car or truck. The Boston Cyclists Union has an online petition which you can sign to support this effort and be kept up-to-date on other ways you can make a difference. The Longfellow is a critical link between Boston and Cambridge, and we need to make sure that, in 2018, it’s built with safety in mind, so that more of us will feel comfortable trading four wheels for two for a trip to the big city.

Throughout the rest of the semester, we will be writing about local issues in transportation and what is being done about them (and what you can do about them!). If there’s something in particular you want to learn about, please feel free to reach out and we’ll see if we can include it in one of our columns!

Dustin Weigl is a dual masters student in Technology/Policy and Transportation.

Michael Davidson is a PhD student in the Institute for Data, Systems, and Society.

Ari Ofsevit is a dual master’s student in Transportation and City Planning.