Project Fact SheetOur goal is to improve safety and address traffic conditions at the interchange of I-495 and I-90.

Through these efforts, we will improve the movement of people and goods throughout the Commonwealth, today and into the future, supporting economic development statewide, and anticipated growth in the area. Improvements here will benefit all of Massachusetts, making us safer, helping our economic engine run, and making it easier for people to get where we want to go.

We’ve prepared this sheet to give you basic information about the project: flip the page for detailed information on purpose, need, and context. We also encourage you to visit the project website, sign up for email updates, and fill out our WikiMap.

Get Involved

WikiMap: How would you improve the interchange?http://wikimapping.com/wikimap/I495I90.html

Mail comments: Attn Project No. 607977, 10 Park Plaza, Room 4260, Boston, MA, 02116

Project Websitemass.gov/massdot/495-90interchange

Email495-90Improvements@state.ma.us

Project Purpose

The purpose of the I-495/I-90 Interchange Improvements Project is to provide a safe and efficient interchange of the interstate highways I-495 & I-90 (the Massachusetts Turnpike). The project will improve safety and chronically deficient traffic conditions for local and regional movement of people and goods, while also supporting planned growth in the region and accommodating future traffic demand.

Project Need

Between 2011 and 2015, 460 crashes, including two fatalities, were recorded at the interchange. Many of the safety concerns associated with the interchange result directly from geometric and operational deficiencies, including ramp configuration and weaving movements (cars crossing each other’s path while entering and exiting the highway). These radiate onto the mainlines of I-90 and I-495 and result in widespread congestion and safety issues beyond the interchange.

The interchange serves as a major crossroads for commuter traffic, and is used by nearly half of freight truck traffic entering eastern MA. A goal of this project is to make safety and operational improvements to the interchange which will enhance commerce and facilitate economic growth locally and regionally. Effective distribution of goods via truck and rail at CSX’s Westboro Transflo facility frees up rail space for Commuter Rail trains, speeding service and potentially easing congestion further east on I-90.

Project Context

The recent implementation of All Electronic Tolling (AET) on the Turnpike will increase vehicle throughput and lower congestion at the I-495 / I-90 interchange by removing the delay associated with toll booth transactions. Toll plazas are just one form of bottleneck that causes congestion and delay on Massachusetts’ highways, but their removal sets the stage for the project team to design and construct a safer and more efficient interchange, as traffic no longer needs to be routed through the toll booths. A more effective interchange ramp layout will improve safety, traffic flow, and freight operations at this important interstate-to-interstate connection.

The current interchange abuts on all sides the Cedar Swamp Area of Critical Environmental Concern (ACEC) and is adjacent to an active rail line providing service for the MBTA and CSX. It is also bounded by residential neighborhoods and major commercial properties. MassDOT is committed to maximizing safety and operational benefits, while minimizing impacts to the environment and all abutting stakeholders, including residents of the Towns of Hopkinton, Westborough, and Southborough, during and after construction.

The chart below provides an overview of the phases of the project development process.

Detailed Project Information