The City of Calgary operates a computerized traffic signal management system that allows City traffic engineers to monitor and control the operation of The City's traffic signal network. The system is known as Management Information System for Transportation, or MIST. MIST was developed by Telvent Farradyne in Rockville, MD and is used in many major urban centres.
There are 980 traffic signals in Calgary, 549 of which are connected to the MIST system. This includes all of the downtown area and the major traffic carriers such as Macleod Trail, Crowchild Trail, 16 Avenue North and Blackfoot Trail.
MIST monitors the traffic signals for proper operation and collects data on traffic flow, such as volumes and speeds from vehicle sensors at the intersections. The signal system interacts with the LRT system, some of the bus routes and some of the fire routes by providing priority for these vehicles.
The MIST system can override the normal operation of traffic signals if and when necessary. Special events like hockey games at the Scotiabank Saddledome or concerts with large attendance or even major road construction may require a short term adjustment to the signal timing.