State planners have drafted proposals for easing congestion and boosting safety at and around two interchanges on Interstate 495.
I-495 and Mass. Pike
The problem
► Vehicles exiting one highway and entering another must weave between other vehicles that are heading toward different ramps, creating congestion and leading to collisions.
Short-term recommendations
► Install additional signs to give motorists directions to the proper toll lanes earlier in their approach to the ramps.
►
Flatten the curve of the onramp to I-495 northbound,
currently the site of frequent truck rollovers.
Estimated cost
► $3 million
Long-term recommendations
► Add a direct connection from I-495 north to the eastbound Mass. Pike (Interstate 90), eliminating the need for motorists making this connection to weave past other traffic.
► Expand the I-495 south offramp and widen I-495 south’s onramp to reduce congestion.
► Redirect the ramp for vehicles shifting from the westbound Mass. Pike to I-495 south, keeping them separate from other vehicles long enough to limit the need to merge and weave.
Estimated cost
► $100 million
I-495 and Route 9
The problem
► Some vehicles exiting I-495 must weave in between vehicles entering the highway, creating congestion and leading to crashes.
Recommendations
► Add “braided” ramps that physically separate exiting traffic from oncoming traffic.
Estimated cost
► $23 million to $25 million
Route 9 near i-495
The problem
► Route 9 is congested along its stretch in Southborough and Westborough where it intersects with Interstate 495, a problem projected to become worse with more development.
Recommendations
► Widen Route 9 between Computer Drive and Deerfoot Road.
► Make improvements at several intersections, including signal upgrades and additional turning lanes.
Estimated cost
► $8.4 million to $9.2 million for road widening
► Intersection improvements vary by location.
SOURCE: Massachusetts Department of Transportation