South-metro commuters weary of fighting their way north on Cedar Avenue may get an extra lane for weekday mornings.
The Minnesota Department of Transportation (MnDOT) is studying the possibility of turning one of the southbound lanes into a northbound lane during morning rush hours, blocking it off with a temporary barrier. It would be the metro area's first reverse-flow "zipper" lane.
It's an ideal road to try such a lane because a huge majority of morning traffic on Cedar heads north, the department says. With 80 percent of the traffic on the freeway heading north during morning rush hours, one of the lesser-used southbound lanes could become a northbound MnPass lane for buses, carpools, motorcycles and solo drivers willing to pay the posted fee.
For a reverse-flow lane, the ideal is a 60-40 split to ensure there is enough spare capacity to safely borrow a lane to reduce congestion, said Jon Solberg, MnDOT's south area planner. With an 80-20 split, "we really have a big differential on the corridor that allows us to do that."
The lane would be created by a line of movable concrete barriers that would separate north and south traffic.
The barriers, linked by steel connectors, would be moved back and forth from the shoulder with a barrier-transfer machine known as a zipper machine. The action of the truck moving the barriers looks like the opening and closing of a big zipper.
Zipper lanes are already in use elsewhere around the country.
Cedar, a key commuter route also known as Hwy. 77, carries an average daily traffic load of about 73,000 vehicles, about 14,000 of which are heading north in the morning.