Within a construction zone, there are times when two lanes of traffic must be merged into one lane.

When traffic is light, this isn’t a big deal. A simple lane change keeps the flow of traffic moving at normal speeds… and an early merge is the most effective course of action.

However, as traffic volumes increase, most drivers believe that the sooner they get out of a blocked lane the better.

But in moderate to heavy traffic, that quite often can create backups as early mergers believe other drivers are bypassing the line and cutting in front of them right before the lane ends.

When traffic is heavy, the zipper merge or late merge, is the most effective and safest way to get through a work zone.

A zipper merge is when drivers use both lanes up until they reach the closure, and then alternate into the open lane. This late merge maximizes road space and can reduce congestion significantly…

Smart work zone technology traffic sensors will detect when vehicles begin to slow down as they approach the work zone. Message boards close to the work zone will instruct drivers to use both lanes as they approach the merge point and then to take turns at the point that the number of lanes reduces.

Further away from the work zone, message boards will alert traffic of slowed or stopped traffic conditions ahead. These messages will give specific distances to the slowed or stopped traffic.

Again, when traffic is really backed up the best plan is not to merge early. Drive in both lanes until you get to that merge point, and then take turns moving into the through lane.

You know… like teeth on a zipper.