Two more states hop on board with the 'zipper merge'

KANSAS CITY, Mo. — Transportation officials in Missouri and Kansas are encouraging motorists to resist the urge to get in line at the first sign of an upcoming lane closure.

Advocates of the "zipper merge" method say using both lanes for as long as possible shortens lines in construction zones by up to 40 percent. They say it doesn't get drivers through the zone any faster, but it reduces the risk of accidents and eases driver angst.

Missouri started promoting the technique earlier this year ahead of a heavy summer construction season. Kansas followed with a pilot project that started last week using electronic signs to warn drivers of an upcoming merge and encourage them to use both lanes.

Minnesota started promoting the zipper merge idea in 2011, and Washington followed in 2014.