Trying to pass on a two-lane highway can be frustrating and dangerous. In order to help make Missouri highways safer and reduce fatalities and disabling injuries, MoDOT has embraced the concept of a shared four-lane design on certain routes.
A shared four-lane consists of an additional lane added to one side of a conventional two-lane highway to provide motorists a chance to pass without having to find gaps in the on coming traffic.
The passing lane alternates between the north and southbound or east and westbound lanes giving motorists from both directions ample opportunity to pass.
The shared four-lane is safer because motorists never have to drive into a lane with oncoming traffic. It also has a paved shoulder, rumble stripes both in the four-foot median and on the edjelines and is much cheaper than constructing four-lane roads.
Click on the video link below to see how a Shared Four-Lane Road works.
Video (mp3, 8.84mb)
Brochure (pdf, 826kb)