OTREC research recently helped the Oregon Department of Transportation (ODOT) determine where to place traffic management devices.
Driving down the freeway, motorists usually appreciate seeing lit-up signs with changing numbers that tell the estimated drive time to an upcoming location. These variable message signs (VMS), also called changeable (CMS) or dynamic message signs (DMS), provide drivers with information that helps them make route decisions.
The Federal Highway Administration (FHWA) has put a high priority on the use of VMS to provide travel time estimates to the public.
Drive times on the VMS are estimated based on sensors which measure the speed of traffic, and an algorithm to calculate how the traffic will flow.
Given the many variables involved, it can be challenging to estimate reliable drive times. ODOT is particularly challenged: the Portland area, with its tight, circular freeway system, can become severely congested after only a couple of minor incidents.
That means Dennis Mitchell, ODOT’s Region 1 Traffic Engineer, has an interesting job.
Traffic engineers work to ensure the safety and efficiency of public roadways and transportation systems. Mitchell constantly looks for ways to...Read more