THE ALLSTON INTERCHANGE BOSTON, MASSACHUSETTS
Focus for this month’s LFA falls upon the important I-90 Interchange and related civil engineering works, located in the Boston neighborhood of Allston, specifically situated between the existing toll interchange and the Boston University Bridge.
This critical infrastructure project, often referred to as the Allston Multimodal Project, is at a major entry point to Boston from the west. The project spans the area of the current ageing Allston Viaduct, replacing it with a more compact arrangement at grade interchange. The site is bordered by Soldiers Field Road, the Charles River and the Boston University campus area.
Boston, Massachusetts.
A key component is the new West Station commuter rail hub and improved pedestrian/bicycle access to the Charles River. The project straightens the dogleg curve of the Mass Pike (I-90 ), creating a new neighborhood and transforming the land around the tollbooths and railroad yards. It is in its final approval stage and scheduled to commence in 2027 – overall completion anticipated to be after six to seven years in 2034.
Currently estimated project costs will be in the order of $1.9- $2bn. Unfortunately, some of these dates may be changed to reflect the recent elimination of the previously established Biden government grant/ assistance amounting to in excess of $300m. The resultant anticipated increase in cost to cover this and the recently forecast construction material and labour costs could increase the final outcome to be in excess of $2.5bn.
The change to all-electric tolling has enabled removal of all toll booths from the interchange, facilitated the straightening of the turnpike in Allston and enabled improvements to multi-modal connections. The elected or appointed officials from Allston, MetroWest and Central Massachusetts have been working on the design of this complex project since the spring of 2014.
The state says that it intends to file its federal environmental impact statement – a key document that will nail down the final conceptual design – within the next year. $1.75bn in pledges had been cobbled together, more than half of which would come from Massachusetts taxpayers. It is as yet undecided where the projected shortfall of $750m will come from. It is particularly relevant to note that, overall, highway construction costs in the US continue to rise at an average of almost 10% per annum.
The Boston neighbourhood of Allston.
Interstate 90 in Boston (I-90 ), also known as the Massachusetts Turnpike (Mass Pike) serves as the easternmost tolled segment of the nation’s longest Interstate, running from the New York state line to Route 1A near Logan International Airport at Boston MA. It is worth noting that Logan International Airport is more commonly known as Boston Logan International Airport, but also known as General Edward Lawrence Logan International Airport after whom the airport was named. It is a hub for Delta Airlines, JetBlue, Cape Air and Nantucket Airlines, Envoy Air, Republic Airways, Delta Connection and Servant Air and is an important transatlantic route for many others.
It handles some 410 million passengers per year, with 408,000 aircraft operations. It was the first airport I landed at when I moved to the USA as a resident in June 2005 via an inaugural Virgin Airlines flight.
This Highlights the much-needed improvements of the I-90 at its extremity in Boston, an overused element of this route which was built in the 1960s and is now well beyond its design life.
It is estimated that in excess of 100,000 vehicles use this section of the route at weekends and it is well overdue for renewal/improvement. Boston ranks among the top 15 cities in the world for traffic congestion; as of 2025, Boston is ranked as the fifth worst in the US for congestion and 12th worldwide.