This isn’t exactly Southborough news, but a major road project nearby impacts Southborough commuters. Some stages, like one next week, could have temporary ripple effects on traffic in town.
And the ultimate goal includes traffic relief on interstate highways that could have longer term impacts on Route 9 in Southborough. (Hopefully good ones.)
Next week, the I-495/I-90 Interchange improvement project will reach a new stage. The new ramp connecting Mass Pike West to 495 South will open.
The “shift” is scheduled to begin with temporary lane closures this Monday evening, May 11th. The target is to complete the “traffic pattern change” by the next morning. (Bad weather could push that by up to a few days.)
The announcement explains:
Once the new ramp is open to traffic, motorists on I-90 westbound will have to exits to access I-495. The first exit will be for I-495 South, while the second exit will be for I-495 North. Appropriate signage, law enforcement details, and messaging will be in place to guide drivers through the work area.
MassDOT (Dept of Transportation) warns:
Drivers traveling through the affected areas should expect delays, reduce speed, and use caution.
Drivers are encouraged to:
- Download the Mass511 mobile app or visit www.mass511.com to view live cameras, travel times, real-time traffic conditions, and project information before setting out on the road. Users can subscribe to receive text and email alerts for traffic conditions.
- Dial 511 and select a route to hear real-time conditions.
- Follow @MassDOT on X, (formerly known as Twitter), to receive regular updates on road and traffic conditions.
For readers unfamiliar, the project is to completely reconfigure the access ramps between Rte 90 and 495. The project will reduce the amount of looping and revamp passing through an area that was once used for tollbooths.
According to MassDOT, this is one of the biggest highway projects they have ever taken on. They estimated that on an average day over 200,000 vehicles and 50% of the state’s commercial traffic pass on or through the interchange.
A 2023 video by MassDOT explained that the change will reduce chronic congestion and backups. But it’s also about improving safety. A representative reminded that the old routing was designed for cars to stop and pay tolls. The new design will eliminate problematic “geometry” to reduce rollovers and “substandard traffic weave” to reduce crashes.
I took a look to see what the next stages of the project are. Highlights from the project site include:
- The new ramp from I-90 Westbound to I-495 Northbound is anticipated to open in Summer 2026.
- Westbound traffic on I-90 is anticipated to shift to the new Railroad Bridge structure in Summer 2026.
- During the second stage of work on the bridge that carries I-90 over the Whitehall Brook, the ramps from I-495 northbound and southbound to I-90 westbound (Exit 58) will be reduced from two lanes to one lane through Summer 2026.
- The project team anticipates opening the new Exit 58 (from I-495 to I-90 Westbound) in Summer 2026.
- Approximately four weeks after new Exit 58 opens, the I-495 southbound alignment will shift to the new structure.
- Additionally, I-495 Northbound traffic will be shifted into the crossover through Fall 2026.
You can read the full project status here.
