Malfunctioning Signals

To request repairs of damaged or non-working traffic signals, contact Operations & Maintenance:

Public Works Traffic Operations
3505 N. Dries Lane
or call (309) 494-8854

After hours, weekends or holidays, contact:

Traffic Division of the Peoria Police Department
(309) 494-8259

Flashing Yellow Turn Signals

Illinois Department of Transportation
(309) 671-3333

You may have noticed a change in the traffic signals in Peoria. The Illinois Department of Transportation has been converting many of the signals in the Peoria area to a flashing yellow left turn signal. According to IDOT, “The Federal Highway Administration conducted a national study that shows the new signal helps prevent crashes, moves more traffic through an intersection, and provides additional traffic management flexibility for agencies.”

To download an instructional brochure, click here.

To view a brief informational video, go to the Illinois Department of Transportation YouTube website at www.youtube.com/user/IllinoisDOT

Traffic Signal Coordination

Public Works Office of Traffic Engineer
3505 N. Dries Lane
(309) 494-8850

The City of Peoria attempts to coordinate, or synchronize, the traffic signals to provide safe and efficient traffic flow throughout the City. This coordination is accomplished by allowing the signals to be able to communicate through controller boxes at each intersection and at the Dries Lane facility. The ability to provide good coordination on a corridor is generally a function of signal spacing, prevailing traffic speed, amount of traffic, roadway capacity, signal cycle lengths, and conflicts with other major roadways. Not only does traffic signal coordination serve the greater good of the traveling public, but also has the added benefits of reducing fuel consumption and emissions, because it reduces overall traffic delay.

Nearly every signal within the City is interconnected by fiber optic or twisted pair cables to form a system of coordinated roadway corridors. These corridors are typically the major arterial roadways, with the most traffic, within the community, such as the Knoxville Avenue, University Street and War Memorial Drive corridors in Peoria. Often these major roadways intersect, which complicates coordination efforts. Also, these main corridors can sometimes involve multiple jurisdictions, such as IDOT, Peoria County and the City, adding to the complexity of coordination.

The predominate goal of a coordinated traffic signal system is to provide the most efficient service to the majority of the traveling public. This is why many drivers on minor roadways will find themselves waiting to cross a major roadway, even if it doesn’t appear that there is enough traffic to justify this extra delay. Often, it serves more traffic for the side street to wait a little longer so that more traffic from downstream on the major roadway will clear the intersection.

In addition, except for in the Central Business District, all majority of the Peoria traffic signals use video or pavement loop detection systems to actuate the signal timing. This allows the signal to adjust the length of a phase of traffic, such as a left turn, to accommodate current traffic load. This type of system helps clear the intersection and reduce the overall traffic delay. Another benefit of actuated signals are that they allow the controller to know when a vehicle from the side street approaches the intersection, which is particularly important at night, because it allows the signals to maintain green signals on the main road and only call for the side street green to be activated when needed.

Another method that the City uses to make traffic signals more efficient is to adjust the signal timing schedules in the AM, PM and midday peak periods for certain corridors. This allows the traffic signals to better serve the traffic during those heavy periods by giving the heaviest traffic movements longer green times to accommodate the additional vehicles.

We also look at ways to improve the system. Recently several Signal Coordination and Timing (SCAT) studies have been performed on portions of the Knoxville Avenue, War Memorial Drive and Washington Street corridors, within the City of Peoria. SCAT studies are corridor wide reviews of the traffic signal coordination programming to find the most efficient use of the equipment to handle the traffic load. Once the studies are done these optimal signal timings can be set in the field in the traffic controllers units. As of 2011, a new SCAT study is being performed on North University Street between Glen Avenue and Forrest Hill Avenue, to increase the efficiency of this corridor. With traffic changes due to development, business changes and adjustments like the recent addition of the flashing yellow turn signals, traffic patterns change and new SCAT studies are needed. It is hoped that about every five to ten years the SCAT programs can be reviewed and adjusted as needed to keep traffic moving efficiently.

Are all the traffic signals coordinated?

A majority of the signals in Peoria are coordinated, however some are not. Signals that are in isolated locations or in too tight of a network do not lend themselves to good coordination. These intersections are often run in a free mode and change on the demand of traffic volumes. In the downtown area, where the streets are laid out in a grid fashion, it has been found that the signals run more efficiently pretimed with short cycle lengths. The downtown intersections are still coordinated on some of the streets that have good progression, however on other downtown streets, that do not have good progression because of the close proximity of the intersections, they are not coordinated. Downtown intersections have fairly equal amounts of traffic in all directions and a short cycle length limits the amount of time that any one direction will need to wait for a green light. Also, as the City grows and new signals are added they are not in some cases connected to the coordinated systems. The signal at Allen Road and Wilhelm Road or new signals north of Route 6 on Knoxville are not yet connected. As development and traffic warrant these signals will be added to the interconnected system.