State report tracks where traffic slows to a crawl
THE BAKER ADMINISTRATION’S congestion study put some hard data behind the public’s sense – correct, as it turned out – that Greater Boston’s already bad traffic got worse in the past five years.
In addition to making more general findings, the report also identified the top five severest occurrences of congestion, and the most consistently congested corridors. One caveat: The study had only limited access to data on local roads, so it focuses on interstates and state roads.
The most severe occurrence of congestion is around 7 a.m. on Interstate 93 southbound in Medford when traveling less than three miles takes an average of 10 and a half minutes. Without traffic it takes less than a third of that time to travel the less than three miles.
After Interstate 93 in Medford at 7 a.m., the next-most severe congestion occurs on Route 2 eastbound near Alewife at 8 a.m.; on the Southeast Expressway northbound from the Braintree split at 7 a.m; on Route 2 eastbound by Alewife at 7 a.m.; and on Interstate 93 southbound at 8 a.m., according to the study.
Many of the congested roadways cut through cities in Greater Boston that will be served by the Green Line extension, a trolley project promised as transit mitigation for the Big Dig.
One of the nine most consistently congested corridors is Route 28 from Cambridge to Medford – which is heavily congested between 7 and 16 hours per day, on average. The state recently installed protected bike lanes along part of that road near the Museum of Science, where a bicyclist was hit and killed last November.
The other eight most congested corridors are Fresh Pond Parkway; Interstate 93; Route 1A between Revere and Boston; American Legion Highway in Revere; Morton Street and Gallivan Boulevard in Dorchester; Route 27 from Whitman into Brockton; parts of Route 9; and the Sagamore Bridge. Outside the Boston area, Route 24 down to the South Coast is consistently congested, as is Route 3 between Interstate 95 and the New Hampshire border; the Massachusetts Turnpike inside Interstate 495; and Interstate 91 in the Springfield area.
WORST TIME TO TRAVEL IN GREATER BOSTON
The worst time to travel in Greater Boston is between 3 p.m. and 6 p.m., when people are heading home from work.
According to the Transportation Department study, approximately two-thirds of the major roadways inside Route 128 during that time period are either congested (average travel times up to twice as long as “free flow” conditions) or heavily congested (average travel times are more than twice as long as free flow).
Mornings between 7 a.m. and 9 a.m. are also bad, but the numbers are a bit better – major roadways are congested or highly congested between 48 percent and 55 percent of the time.
Overall, major roadways inside Route 128 experience some level of congestion from 5 in the morning to 8 at night, making the area far and away the worst for navigating as a driver. “We’re starting to see parts of the network that are congested all day long,” said Transportation Secretary Stephanie Pollack.
The notion of off-peak travel on many Greater Boston roadways is rapidly disappearing, but there are exceptions. The Sumner Tunnel, where congestion is extremely intense from 5:30 a.m. to 9:30 a.m. and from 2:30 p.m. to 4:30 p.m., is relatively congestion-free the rest of the day.
Outside of Greater Boston, there is a big dropoff in congestion. The major roadways between Route 128 and I-495 have some, but then it falls off considerably. In central and western Massachusetts and the South Coast, the percent of congested roadways at any given time rarely rises above 10 percent and is frequently 0 percent.
The major congestion spots outside Greater Boston are the Sagamore Bridge, Route 27 between Whitman and Route 214, Route 3 southbound from the New Hampshire border to Burlington, Route 24 between Brockton and Route 128, and I-91 southbound in the Springfield area between 4 p.m. and 8 p.m.
DISSECTING UBER AND LYFT DATA
Uber and Lyft, which marry 21st century smartphone technology with the more longstanding idea of on-demand automotive livery service, have caught a lot of the blame for the contributions they make to Boston’s traffic problems.
The two competitors teamed up to commission a report by Fehr & Peers this month, which found that Uber and Lyft drivers accounted for about 7 to 8 percent of the road miles in Suffolk County, which includes Boston, in September 2018. The Baker administration study released Thursday found ride-hailing companies accounted for 4.4 percent of all trips in Boston in 2018, and an even smaller percentage of trips in Cambridge, Somerville, and Brookline.
Despite the numbers, Gov. Charlie Baker appears to be warming to a proposal pushed by Boston Mayor Marty Walsh to increase the fees for car rides that can be hailed by smart phone. The state study indicates the Baker administration looks forward to collaborating with lawmakers who want to ramp up fees on the ride-hailing apps, but the apps themselves say they favor levying fees on all cars in congested areas.
“We support Governor Baker’s goal of reducing congestion in the Commonwealth and look forward to working with him and doing our part,” said Uber spokesperson Alix Anfang. “As the report notes, rideshare vehicles represent a small fraction of cars in Boston and across the state. To have real impact, any additional fees should target all vehicles at the most congested areas and times so that people who have limited access to mass transit aren’t punished.”
The Baker administration wants more access to data from ride-hailing companies, and Transportation Secretary Stephanie Pollack said the average usage of the services doesn’t give the full picture of the jams Uber and Lyft can cause.
“As a percentage of total traffic, you cannot say that transportation network companies are the reason for congestion. They are in single digits,” Pollack said. “But depending on where they are and at what time of day – if people are triple parked and can’t get to the curb at rush hour that’s going to be a problem. If they’re in the middle of Kenmore Square, stopping before a Red Sox game, then in that place at that time, they’re much more than 5 or 10 percent.”
PLOTTING VEHICLE VOLUME AND SPEED
Congestion typically rears its head when traffic increases and vehicles begin to bunch up and slow down. We’ve all been there, but data gleaned from the state’s tolling system shows how traffic volumes affect speed.
On the Turnpike outside of Greater Boston, traffic volumes go up and down over the course of a day but speeds rarely vary because the number of vehicles rarely exceeds the capacity of the roadway. At the Ludlow toll gantry on the Turnpike, for example, average speeds constantly exceed the posted speed limit of 65 miles per hour no matter the time of day. The same is true in Southborough, with the exception of specific times in the early morning or afternoon when traffic reaches high levels.
In Newton, by contrast, traffic volumes are significantly higher, triggering corresponding declines in speed. But sometimes the speed drop seems excessive. During the afternoon, for example, speed levels drop to about 30 miles per hour in both directions when the volume reaches 4,200 vehicles per hour. In the mornings, the volume hits about 5,800 vehicles per hour going either east or west, yet the speed drops to 38 miles per hour eastbound and 55 miles per hour westbound.
The Tobin Bridge and the Sumner Tunnel appear to lack sufficient capacity for southbound traffic into the city. In both cases, speeds drop to about 20 miles per hour (Tobin) and 12 miles per hour (Sumner) during morning and afternoon peak travel periods.