Dynamic Lane Merge System being implemented on I-91

22News explains how this new system is supposed to work

SPRINGFIELD, Mass. (WWLP) – MassDOT is expected to launch a new sytem to help with merging through construction on I-91 in Springfield.

Drivers will notice some new message boards this week on I-91 South as they approach the work zone, and the point is to get you through it quicker.

The Dynamic Lane Merge System aims to reduce traffic delays and increase safety where the lanes on I-91 South go from two to one where construction is taking place on the elevated portion of the highway.


Continuing Coverage: I-91 Reconstruction


The system uses real time message boards to tell drivers when and how they should merge based on data collected by sensors positioned along the roadway.  The system is called “dynamic” because it uses traffic data to alternate between guiding vehicles into a “late merge” or “early merge.”

A late merge works best for high traffic volumes and low average speeds due to congestion. The system would instruct drivers to remain in their lanes until the merge point, filling both lanes and taking turns entering creating an efficient zipper effect.

An early merge works best in low traffic volumes with high average speeds, and instructs drivers to merge well ahead of the merge point to avoid slowing down for traffic.