Summer construction projects in Massachusetts are kicking into high gear, including one of the state’s major improvement projects: the I-495/I-90 interchange.

The Massachusetts Department of Transportation said drivers should be on the lookout for detour signs and expect delays.

This week’s work included overnight closures of I-495 southbound lanes to shift them into the highway’s median, which will allow for work to begin on the lanes and shoulder.

The department said the $466 million road project is projected to reduce crashes and make other safety fixes at the heavily traveled interchange at the Hopkinton and Westborough town lines, which carries more than 175,000 vehicles a day — including approximately half of all trucks entering eastern Massachusetts. Officials said that for too many years, traffic demands at the interchange exceeded its capacity.

The construction project includes:

  • Complete replacement of the interchange
  • Elimination of the old toll booth area and weaving areas created by the current design
  • Improved ramp spacing, acceleration and deceleration lanes and elimination of weaving movements
  • A new I-495 bridge over I-90
  • New I-495 and I-90 bridges over the MBTA/CSX/Amtrak lines
  • An auxiliary lane from I-495 northbound to Route 9
  • A new Fruit Street Bridge
  • A new I-495 northbound bridge over Flanders Road
  • Restoration and mitigation of environmental resource areas

The Hopkinton Chamber of Commerce with its 135 members and the 495/MetroWest Partnership, a public-private collaboration with businesses and municipalities, has worked to keep stakeholders updated on the interchange project and its local impact.

JoAnn Parks, general manager of the Hopkinton Country Club, was aware of the bridge work on Fruit Street and contacted transportation officials for help understanding the detours.

“I didn’t know how that would affect us,” Parks said. She posted GPS directions so patrons can circumvent delays getting to the club.

Kelly Grill, executive director of the Hopkinton Center for the Arts, said she expects “some pain points for a while” but believes the outcome will be worth it.

“This area is just growing. Metro is growing leaps and bounds — and that’s a key juncture,” she said. “When it [the construction] is completed, it will be, you know, very beneficial to all the businesses in the area.”

The interchange project is expected to be complete by 2027.