State outlines improvements to congested I-495-Mass Pike interchange
Sunday, March 29, 2015
By Donna Boynton TELEGRAM & GAZETTE STAFF
donna.boynton@telegram.com
WESTBORO — The state Department of Transportation is considering three alternatives for improving the heavily congested, hazardous Interstate 495-Massachusetts Turnpike intersection, ranging in cost from $165 million to $285 million
They are:
• A one-lane flyover at I-90 West to I-495 South that would connect to I-495 by adding a left lane within the existing median. The additional lane would prevent the need for vehicles to merge into high-speed traffic. The new lane would eventually merge into the three-lane highway on I-495; and a two-lane flyover from I-495 North to I-90 East that would connect with I-90 in the form of an acceleration lane and eventually merge into the existing three-lane highway. This improvement would eliminate the weaving that currently exists in the toll plaza area. The total cost for those two fly-overs is estimated to be about $162 million, not including right-of-way acquisitions, mitigation or construction services.
• A one-lane elevated ramp from I-90 West to I-495 North that would cross over the existing CSX/commuter rail and connect as an acceleration lane before merging onto the existing three lanes of I-90. This design would eliminate weaving at the toll plaza, and modify the existing loop ramp. It is estimated to cost about $216 million.
• A more complex plan that incorporates the previous two as well as three new ramps. Those new ramps are a one-lane flyover crossing over I-495 North to I-90 West connecting to I-495 as an acceleration lane before merging into the existing three-lane highway; a one-lane ramp connecting I-495 South to I-90 West; and a one-lane loop ramp crossing over the existing CSX/commuter line connecting I-495 North to I-90 West. This concept design would eliminate the need for the existing toll plaza connector bridge over I-495, as well as the existing loop ramps at the interchange. This plan is estimated to cost $285 million.
http://www.telegram.com/article/20150329/NEWS/303299822/1116