City engineers work to correct traffic signal timing issues

City of Minneapolis engineers are working to correct traffic signal timing issues that are affecting traffic flow in various parts of town, after an Oct. 9 power outage affected the signals’ central computer system. This computer controls about 700 of the City’s 800 signalized intersections.

The system is currently using a backup signal timing plan, which means traffic signals are still following the standard “green, yellow, red” sequence. Typically, the system optimizes traffic flow by coordinating signals at different intersections along a street to keep traffic moving. However, until the computer issues are resolved, drivers may notice that some signals are not coordinated as well as they usually are. With the current computer issues, drivers may notice changes in traffic flow, interrupted travel in some corridors, and potentially increased delays. Hiawatha Avenue signals operate independently of this system and are not affected.

Public Works is working with software engineers to correct the computer issue and estimates it will be several days before normal traffic signal timing is restored citywide. In the meantime, drivers who see significant traffic signal timing issues are encouraged to call 311 to report them. Public Works uses those calls to identify problems at specific intersections. Residents can also report traffic signal issues online on the Traffic website.

Over the last several years, the City of Minneapolis has been moving forward on a plan to replace its computerized traffic signal system hardware and software. The City has been working with the Federal Highway Administration, Minnesota Department of Transportation, Metropolitan Council, Hennepin County and other project partners to secure funding and to identify and design the system components and features for a new traffic signal computer and communication system. The new system will prevent issues like this in the future. The project is set to be put out for bids later this year, and work is expected to be complete in late 2013.

Published Oct 13, 2011