Iteris Delivers New Safety Features In ClearGuide SPM Mobility Software

As USDOT’s National Roadway Safety Strategy continues, Iteris is significantly increasing the safety capabilities of its mobility software ClearGuide® by enhancing the Signal Performance Measures (SPM) component of the solution. Specifically, ClearGuide SPM’s existing Pedestrian and Clearance Interval Activity charts have been upgraded to better estimate, quantify and visualize vehicle-to-vehicle and vehicle-to-pedestrian conflicts. (A conflict is defined as a turning vehicle entering a crosswalk when a pedestrian or cyclist is crossing.)

The USDOT initiative identifies ways to promote safer people, roads, vehicles and speeds. The new ClearGuide enhancements are included in ClearGuide SPM’s standard pricing, and should play a direct role in agencies’ ability to increase public roadway safety.

The features will help agencies:

• Identify intersections with emerging crash trends before crashes happen, using existing infrastructure
• Prioritize operational countermeasures (like signal timing changes) to improve safety
  

ClearGuide SPM operates and provides detailed information at the traffic signal or intersection level. Reducing fatalities and serious injuries at intersections is a major area of focus because:

• Between 2008 and 2019, the National Highway Traffic Safety Administration estimated 9,227 people were killed in crashes related to red-light running
• In 2019 alone, more than 840 people died due to red-light running
• Now routinely at 700 to 900 annually, red-light running deaths are at a 10-year high
• Vulnerable road user deaths are up 12% since 2000, with 800 pedestrians and 135 bicycle fatalities per year occurring at signalized intersections
  

Typically, agencies rely on crash data to identify unsafe intersections and develop countermeasures, but it can take years of crash data to develop statistically significant crash hotspot patterns. Iteris has observed that agencies are increasingly interested in more proactive, data- and technology-driven solutions. One emerging area of interest is near-miss data, which measures narrowly avoided collisions as a proxy for real collisions; the idea is to identify and address crash-risk factors before actual crashes happen. The ClearGuide team realized there was an opportunity to enhance software-based signal timing strategies for measurably improving roadway safety.

The new ClearGuide SPM safety features leverage existing infrastructure to measure, report and alert on vehicle-to-vehicle and vehicle-to-pedestrian conflicts. This infrastructure includes:

• Iteris detection already widely deployed for traffic control at intersections
• Modern traffic signal controllers already installed at intersections
  

Advanced algorithms within ClearGuide SPM then provide information to help agencies proactively prioritize easy-to-implement countermeasures like Leading Pedestrian Intervals and Red Protect, all before crashes happen. Because these features are integrated into the ClearGuide SPM software, the agency has the full context of the signal operations at the intersection to make adjustments to improve safety.

Clearance Interval Activity

ClearGuide SPM users can now use the Clearance Interval Activity chart to investigate red-light running complaints and request red-light running data beyond 2 seconds past the end of red clearance. Users can also investigate complaint calls of red-light running to see if they are sustained problems or one-off incidents. This can inform where law enforcement may be needed.

The Clearance Interval Activity chart identifies intersections and timing plans where high rates of red-light running are resulting in potential conflicts. Possible countermeasures to this include:

• Improved coordination including offset adjustment or additional green time
• Reduced cycle lengths (if Wait Time is set too long, this potentially frustrates drivers and incentivizes red-light running)
• Increase yellow change interval or red clearance interval (ClearGuide SPM Clearance Interval Activity shows what these values currently are)
• Implement dilemma zone detection to extend the green interval until the vehicle is through the zone
• Delay the onset of green for opposing phases with the Red Clearance Extension controller setting
  

The Clearance Interval Activity chart

Pedestrian Activity

On the pedestrian side, ClearGuide SPM users can now use the Pedestrian Activity Chart to rank intersections and assess design improvements, for example at bike trail-roadway crossings.

The Pedestrian Activity chart identifies intersections and timing plans where there are high rates of vehicle-to-pedestrian conflicts, such as when a vehicle turns into a crosswalk while a pedestrian is crossing there. Possible countermeasures to this include:

• ClearGuide SPM Leading Pedestrian Intervals, i.e., giving pedestrians 3 to 7 seconds of walk sign before the permissive turning movements get the green
• Protected turn phases
• Pedestrian countdown timers
• Exclusive pedestrian phases
• Street lighting enhancements
  

The Pedestrian Activity chart

While there are specialized video detection solutions focused on near misses, Iteris is unique in offering an SPM tool with this level of focus and execution on safety use cases. Any city, county and state agencies that own and operate traffic signals, as well as metropolitan planning organizations that fund signal timing projects, should contact Iteris for more information or to schedule a free demo.