Southeastern Regional Planning & Economic Development District

PROJECTS & PARTNERSHIPS - I-495 CORRIDOR
IN THIS SECTION:	IN PROJECTS & PARTNERSHIPS
I-495 Executive Summary Results of the Study Recommended Congestion Improvements Safety Issues Reports	Commuter Rail MPO Taunton River Vision 2020 Sustainability/Futures Task Force Expedited Permitting I-495 Corridor Casino

I-495 Executive Summary:

The intent of this study is to examine existing and future traffic congestion on Interstate 495 and its interchanges between Route 24 in Raynham and Interstate 195 and Route 25 in Wareham. Presently, I-495 north of Route 24 and south of I-195/Route 25 provides three travel lanes in each direction. The segment to be studied between these two locations provides only 2 lanes in each direction. This results in a bottleneck that causes traffic congestion at times during evening peak periods and in the summer months.

In 2003 and 2007, the Southeastern Regional Planning and Economic Development District (SRPEDD) published regional transportation plans that identified a portion of the Interstate 495 corridor as a future congestion problem. This report examines a 15 mile section of I-495 between Route 24 in Raynham to I-195 in Wareham. The study evaluates the existing operation of this 4 lane highway to determine if additional travel lanes will be necessary to address future traffic congestion.

Results of the Study:

Roadway Congestion
There are several areas along the I-495 highway corridor that have existing or will have potential congestion due to additional economic development in the area. These areas identified in this report include:

I-495 North of Route 44 - Presently experiences occasional congestion (LOS D) during the AM Peak Hour northbound and PM Peak Hour Southbound.

Congestion is forecasted to worsen (LOS F) by 2030 along the two lane section of the highway north of Route 44 during the morning and evening peak hours. During the off peak hours, the highway operates at or above acceptable levels of services.
Route 44 corridor and the Middleborough Circle Rotary congestion impacts existing ramp congestion at Exit 6. I-495 southbound off ramp traffic to Route 44 queues down the ramp and back onto the southbound through lanes of the highway. This congestion is expected to continue if improvements to Route 44 and the removal of the Middleborough Rotary are not implemented.
Future ramp congestion at the interchanges of Exit 2 (Route 58) and Exit 3 (Route 28) are expected with added development in the southern portion of the study area. Congestion at these unsignalized locations results from the left turning traffic delayed due to an opposing heavy through traffic.

Recommended Congestion Improvements

Replace Middleborough Rotary & Widen Route 44

Route 44 has been studied on 2 separate occasions by MassHighway, but has never been completed through the public process. As a result, the unofficial recommendation stated that Route 44 will require a widening from its existing undivided 2 lane road to a divided 4 lane facility. The preliminary design plans indicate an elaborate ring road configuration to replace the existing Middleborough Rotary. The replacement of the rotary with a grade separated Route 44 from Route 18 and Route 28 will improve traffic flow along Route 44.

Improving traffic flow on Route 44 will eliminate the exit ramp queue that impacts the I-495 southbound traffic flow and safety problems. An estimated reconstruction cost for the Ring Road improvement design is $136 million in 2007. This cost rises to approximately $245 million by 2015.

Also, there are several wetland issues in the southern sections of the improvement project near the intersection of the ring road and Route 18. These wetlands also exist in the vicinity of the new ramps proposed to access the Ring Road from I-495 northbound. The engineering design and eventual implementation of this improvement must carefully consider these sensitive environmental areas.

Widen I-495 to 3 lanes in either direction north of Route 44

Due to projected congestion during the peak hours, a major widening of I-495 to add a third travel lane northbound and southbound is needed for approximately 3.5 miles between Route 24 to Route 44. This added capacity would improve the existing projected congestions during the AM (northbound) and PM (southbound) peak hours to an acceptable LOS C.

A major widening will impact 3 bridge locations; Route 44, Vernon Street, and the Taunton River.

With a future widening of I-495, several environmental issues will require attention and mitigation.
These issues include:

impacts to rare and endangered species,
archaeological evidence indicate a number of native American tribes settled in the vicinity of the
Taunton River and I-495,
Taunton River provides foraging, nursery and migratory habitat for a variety of fish and shellfish.

It is estimated that a widening project for both directions of the highway will cost nearly $86 million. This estimate increases to approximately $203 million by 2030, when the capacity is needed to meet the anticipated traffic congestion. These estimates do not include the replacement and widening of the bridges located at Route 44, Vernon Street, and over the Taunton River. It also does not include the environmental mitigation that will be necessary along the corridor and for the Taunton River.

Interchange Improvements

Additional traffic resulting from increased development will cause additional congestion at the interchange ramps of Exit 2 (Route 58) and Exit 3 (Route 28). The implementation of traffic signals may be warranted to resolve these congestion problems. Since the congestion would occur as a result of increased development, the surrounding communities and MassHighway should continue to monitor these interchanges and insist the developers participate in mitigation to avert this congestion. This can be done as part of the Massachusetts Environmental Protection Agency (MEPA) review process, but should also be considered for smaller projects that are below the MEPA threshold.

Safety Issues:

There are sections along the I-495 corridor that have existing safety issues requiring mitigation. Although these improvements cannot insure the prevention of crashes, they are intended to improve a motorist’s chances of surviving a crash without severe injury or death.

The short distance on I-495 southbound between the Route 44 on-ramp and the Route 18 off-ramp prevents safe weave maneuvers for traffic. It is expected to remain a problem which could worsen as traffic volumes increase.

Recommended Safety Improvements

Additional guard rails are necessary at several locations to prevent lane departure crashes
and potential loss of lives,
Cable barrier should be placed within the median along the entire 8+ mile length of the I-495 study area where the median is narrow, currently unprotected and very crossable. The area extends from a point approximately one half mile south on Exit 3 to nearly one half mile north of Exit 6.
Exit 4 at Route 105 - The crashes at Route 105 are related to periods of commuter traffic heading to and from the nearby commuter rail station in Lakeville. The installation of traffic signals at both intersections, estimated at $1,100,000, is programmed in the region’s Transportation Improvement Program (TIP) for fiscal year 2010.
Exits 5 (Rte 18) and 6 (Rte 44) & the Segment between Rte 44 and Rte 24 - The northbound ramps from both Bedford Street (Route 18) and Route 44 have acceleration lanes that are shorter than AASHTO standards. Modifications to these ramps should be considered.