"Do Not Pass When Flashing" signs require motorists on eastbound I-96 in Crockery Township to merge into a single lane well before a lane is closed for the state Route 231 construction zone. When activated, the signs create a no-passing zone ahead of the section of road where there's one lane open in each direction.
The state agency said the so-called dynamic merge lanes are being used to head off the possibility of aggressive driving and late merges.
"It's all about safety," said John Richard, a spokesman for MDOT in Grand Rapids.
According to state police, drivers who don't merge ahead of the "Do Not Pass" signs when they are flashing could face a ticket.
MDOT began using dynamic merge lanes in some work zones a few years ago and research is evaluating the effectiveness of such lanes. The I-96 project runs until November, and the state agency will be able to further evaluate the merge lanes.