REGIONAL NEWS
REGION III
Illinois Introduces Screening System for Flat Tires at Weigh Stations By Rich Telford, Weight Enforcement Engineer, Illinois Department of Transportation; Master Sgt. Todd Armstrong, Illinois State Police; Tom Der, Vice President, ITS Solutions and Engineering, International Road Dynamics Last spring, the Illinois Department of Transportation (IDOT) and Illinois State Police (ISP) performed a site acceptance test at the I-55 Williamsville (SB) weigh station to evaluate the effectiveness of the Tire Anomaly and Classification System (TACS™), a new screening technology developed by International Road Dynamics (IRD) for identifying vehicles with flat tires. TACS uses an array of in-road sensors that measure tire “footprints.” When a vehicle passes over the sensors, data from the tires are sent to the roadside electronics. From there, the weigh station software evaluates whether a tire problem should be flagged for the vehicle. During the test period, 205 vehicles were flagged as having flat tires, one vehicle was identified with a completely missing tire and 33 vehicles had mismatched tires with a significant difference in diameter. Inspectors filled out forms to confirm that tires identified as flat by TACS met the outof-service criteria. Following the successful evaluation, IDOT commissioned IRD to expand the deployment with the installation of two more TACS at the I-55 Bolingbrook and I-70 Marshall weigh stations in October 2018. IDOT plans for three more TACS to be brought online in spring 2019.
12
GUARDIAN
In Illinois, TACS was installed on ramps approaching weigh station facilities to identify vehicles that are unsafe due to missing, flat or mismatched diameter tires. The systems identify vehicles that meet these criteria, enabling ISP personnel to select vehicles for further inspection. Inspectors verify the tire problems and commercial motor vehicles with missing or flat tires can be placed out of service. The driver will be required to fix tire problems before leaving the inspection station. ISP sees the importance of tire safety screening, as tires are a frequent vehiclerelated factor in fatal crashes. Tire anomalies and flat tires decrease directional control, increase the risk of catastrophic failure, and negatively impact tire life and fuel economy.
all commercial motor vehicles on the weigh station ramp. The Bolingbrook TACS site was deployed in October 2018 and TACS was installed at the Marshall weigh station in November 2018. Aggregated data from the three sites indicate a rate of tire anomalies of 1.37 percent. TACS is configured to identify flat tires specifically to ensure that all vehicles flagged for inspection will meet the out-of-service criteria. As expected, this results in a lower number of tire anomalies identified than the total rate of out-of-service tire problems identified in inspections.1 However, setting a higher tolerance focuses on the most unsafe vehicles and ensures that inspectors are not occupied with inspecting tires that have low pressure but do not meet the out-of-service criteria.
Underinflation, especially combined with overloading, leads to tire damage that can cause blowouts and potentially crash-causing rubber debris. TACS inspections have also helped reduce the amount of road debris caused by damaged tires. This, in turn, has reduced time spent by ISP collecting the debris, which must be picked up and disposed of by the agency to ensure the safety of road users.
Software and Reporting
Since May 2018, the TACS installation at the Williamsville weigh station has been screening
If a vehicle has a tire anomaly, the record includes a TACS tab that the operator may
Illinois TACS is integrated into IRD’s Operator Workstation software. Vehicles with an identified tire anomaly will automatically be directed by lane signs to report to the weigh station, and a tire anomaly warning and highlighted axle will appear on the vehicle record. If enabled, an audible alarm will sound to notify station operators of the tire issue.