Route 20, Boston Post Road, Highland Street up next for safety changes

As residents await construction at one crash-prone Route 20 intersection, the Massachusetts Department of Transportation (MassDOT) is reviewing proposals for the troublesome Route 20, Boston Post Road and Highland Street intersection.

The triangle-shaped intersection has been the site of numerous crashes over the last decade and has often been ranked in the top 5% of high-crash locations in the Metropolitan Area Planning Council’s jurisdiction, which covers 101 municipalities in eastern Massachusetts. 

For years, the town has explored safety remediation. With construction expected to begin soon at the intersection of Route 20, Boston Post Road and Wellesley Street, the Traffic and Sidewalk Committee is eyeing Highland Street next, particularly as the number of vehicles on the road increases.

“The further east you go [on Route 20], the more traffic you pick up,” said Richard Flynn, chair of the Traffic and Sidewalk Committee. “We’re approaching 25,000 cars a day, which is a very significant volume.”

Police Capt. Thomas Kelly, an ex-officio member of the Traffic and Sidewalk Committee, said it is a “concerning intersection,” with 57 crashes reported from 2022 to present. The majority of accidents result from drivers crossing traffic, particularly those exiting Highland Street onto Route 20, according to Kelly.

Additional data from MassDOT and the engineering firm Vanasse Hangen Brustlin (VHB), shows the intersection has been crash-prone for many years, with 71 crashes reported from 2015 to 2019. The majority of incidents in both five-year periods resulted in property damage only. Most collisions occurred between 4 and 6 p.m. on weekdays.

To address safety concerns, Weston engaged VHB to study the intersection, with residents appropriating $413,400 for design and permitting fees at the 2022 Annual Town Meeting.

 In 2023, the Traffic and Sidewalk Committee and the Select Board endorsed a plan to consolidate the roads into a standard four-legged intersection with a traffic light. The proposal would eliminate the existing Boston Post Road connection to Route 20 and shift all traffic to where Highland Street meets the Boston Post Road bypass to create a traditional intersection with a traffic light.

Preliminary state construction estimates are about $6.24 million.

Preliminary designs were sent to MassDOT in 2024, and have been actively developed further in the state’s Intersection Control Evaluation. 

Flynn said VHB’s traditional signalized proposal is being compared to a roundabout, the state’s preferred choice. Each option has benefits, Flynn said, with a traffic light offering easier movement for pedestrians and cyclists but stops cars completely, while a roundabout keeps traffic moving at a slow pace.

“We really have to take a look at what the data says,” Flynn said. “We want to understand the assumptions and the data that went into [MassDOT’s] calculus.”

A broad view of Route 20

As the town works with MassDOT to reach a final design for the Highland Street intersection, Flynn said he believes the Traffic and Sidewalk Committee, as well as the state, should start to examine a wider view of Route 20, rather than address each concern individually.

His top issue, he said, could be too many traffic lights snarling traffic, exacerbating the already-frustrating wait times during the daily commute.

When the signalized intersection is complete at Boston Post Road, Wellesley Street and Route 20, there will be three traffic lights on Route 20 in Weston. Add another one at Highland Street – if that is the solution the state and town agree on – and there are now four opportunities for traffic to be stopped on the state road, which Flynn said could lead drivers to drive through the town center to try to avoid delays.

The opening of Modera Weston less than half of a mile west could also pose traffic concerns as residents living there try to turn onto Route 20.

“We’ve been highly focused as a committee on Route 30,” Flynn said. “We’ve got to take a broader view [of Route 20, too].”