77 crosswalk sees timing adjustment

July tweaks reduce congestion during detour, slow down pedestrians

Urban Studies and Planning lecturer Ezra H. Glenn felt like he was waiting longer this year to cross the street at 77 Massachusetts Avenue, so he emailed Cambridge’s planning office “at the risk of sounding like a crank” and found that, indeed, ten seconds had been added to the length of the green light for vehicles.

“This intersection is programmed for 30 seconds [pedestrian] and 70 seconds vehicle in the rush hours,” Jeffrey R. Parenti, principal traffic engineer for the city of Cambridge, wrote in an email to Glenn. He says that he increased the vehicle time from 60 seconds back in July “to account for the additional traffic from the [Longfellow] Bridge detour.”

According to the Massachusetts Department of Transportation’s website, the detour around the bridge will be in effect throughout the three-and-a-half-year Longfellow Bridge Rehabilitation Project, which closes the bridge to all northbound automobile traffic from Boston to Cambridge, according to the Massachusetts Department of Transportation’s website. The renovation project started last summer.

In an interview with The Tech, Parenti said that Mass. Ave. has experienced a predicted increase in traffic since the detour began and that the traffic lights were adjusted as far north as Sidney Street as part of the detour. He said that the signals will likely revert back to their 90-second cycles once the Longfellow Bridge repairs are completed.

In addition, Parenti pointed out that the extra traffic makes it especially important for the 77 Mass. Ave. signals to sync with those at the Memorial Drive intersection, which runs on a 100-second cycle and is operated by the Massachusetts Department of Conservation and Recreation rather than the city of Cambridge.

“The advantage is that if you’re traveling [north, the direction of the detour,] along the Mass. Ave. corridor, you get coordinated greens,” Parenti said.

For pedestrians, ten more seconds of waiting to cross the street may not seem like much in theory, but it seems to make a difference in practice, at least to some.

Glenn acknowledged that urban planning involves these “little details and tweaks,” but warned that “something that benefits the cars and prevents gridlock may also frustrate the pedestrians and lead to jaywalking or getting stuck in the rain.”

“I was surprised that I noticed it,” Glenn said. “I just felt that it seemed longer.”

Several others, however, did not notice the change. For example, Patrick M. Hurst G told The Tech, “I think it’s been the same all 5 years [I’ve been here].”

1 Comment
Anonymous about 10 years ago

Permanently changing the light timing so the #1 bus doesn't hit every single red would save thousands of person-hours every day, not to mention saving the T money.