Coordinated signals

What is signal coordination?

Signal coordination works with signal optimization to help time signals along a corridor to allow traffic to move as efficiently as possible through the corridor with minimal stopping, when traveling at the posted speed limits. 

Typically, the corridor and direction of travel with the highest level of traffic gets the most time at signals; this process can mean that traffic at side streets feeding into that corridor will typically  wait for a period before being able to enter the corridor, but once they are in the corridor, stops are minimized, as long as the  vehicle travels at the posted speed limit. This can also mean that traffic traveling against the heaviest movements of traffic, for example during morning or evening rush periods, may also stop more frequently. 

To do this, traffic engineers evaluate the corridor.  In an extensive process, they look at each of the intersections on the corridor and how much traffic goes through or turns left or right onto or off the corridor. Once they gather all this data, they develop a signal timing plan that optimizes the travel time for the most travelers. Since traffic patterns are fluid based, those timing plans can change throughout the day.

Since many of these signals work with each other, and are centrally controlled through the Transportation Management Center, engineers can update the signal timing on the fly if there is an incident on a nearby roadway pushing more traffic than usual onto the corridor.