Low-cost change achieves anticipated congestion relief
BOSTON – Monday, January 13, 2014—This past summer MassDOT implemented a right lane closure on I-95 Northbound, just south of the I-90 (Mass Pike) on-ramp. After an evaluation of the traffic volumes northbound on I-95, it was determined that a three lane section, between the I-95 exit (Exits 23, 24, 25) to the Mass Pike and the I-90 on ramp to I-95 Northbound has adequate capacity during the A.M. and P.M. peak hours to handle the traffic volumes.
MassDOT implemented the aforementioned right lane closure on I-95 Northbound in order to mitigate traffic from I-90, Rte. 30 and Recreation Road trying to access I-95 North. Traffic volumes on I-95 Northbound south of the Mass Pike exit showed the right lane carried 2028 vehicles per hour, with 1582 vehicles or 72% of the volume taking the exit to the Mass Pike and 446 vehicles travelling in the I-95 North right lane north of the Mass Pike, or 28%.
Since the capacity of a lane is approximately 2200 vehicles per hour at 55 MPH and the adjacent lane carries 1666 Vehicles, there is adequate capacity to accept the lane merge. In contrast, the merge from the Mass Pike on-ramp could not handle the merge as the on-ramps speeds are too low. This merging traffic resulted in long queues and delays for the traffic on I-90, Rte. 30 and Recreation Road.
By removing the I-95 Northbound right lane south of the Mass Pike on-ramp, traffic is allowed to enter I-95 NB in an exclusive lane. The volume counted entering I-95 Northbound from the Mass Pike, Rte. 30 and Recreation Road totaled 1272 vehicles per hour prior to the establishment of the exclusive lane. This low count was due to a saturated merge condition at low speeds. With the establishment of the exclusive lane, the merge is now better able to meet the demand of 2000+ vehicles per hour, a count roughly equivalent to the traffic exiting to the Pike.
As a result of the study, MassDOT determined traffic delays on I-95 Northbound resulted in an additional 50 seconds of travel time between the Rte. 9 interchange and Rte. 20 interchange. Delays on I-95 Northbound south of Rte. 9 were not considered as part of the study area. Delays south of this point are impacted by ever-changing, unpredictable factors such as: breakdowns, police activity, and slow moving vehicles which compound delays.
In addition to the minimal increase in traffic time for I-95 Northbound travelers, the study also determined that delays decreased by 18.6 minutes from the Weston State Police Barracks to Rte. 20. This is a dramatic reduction in travel time for an Interstate highway and achieves MassDOT’s original project goal of delivering to our customers a low-cost, effective congestion reduction measure.
In 2009, the Massachusetts Department of Transportation (MassDOT) was created to unify the state’s various transportation agencies. MassDOT now includes the Highway Division, the MBTA and Rail & Transit Division, the Aeronautics Division, and the Registry of Motor Vehicles. MassDOT is committed to providing a safe and reliable transportation system to all those who travel in the Commonwealth and works to deliver excellent customer service. MassDOT has been nationally recognized for its innovative approach to transportation, including the Accelerated Bridge Program, the “Where’s My Bus and Train?” apps and “Fast 14” work. For more information visit MassDOT at our website:www.mass.gov/massdot blog: http://blog.mass.gov/transportation/, of follow MassDOT on twitter at https://twitter.com/MassDOT and Facebook at www.facebook.com/massdotinfo.