Using Signal Trends to Determine Your Back-to-School Congestion Hotspots

With the U.S. academic season back in session, cities and counties are seeing significant increases in vehicular congestion around schools, combined with a sharp rise in the volume of vulnerable road users in these zones.

Using ClearGuide® Signal Trends probe data-based intersection analytics, Iteris looked at the changes in intersection delay before and after school was back in session. In this example, Montgomery County, MD, saw a dramatic increase in congestion levels around schools beginning precisely during the week they were reopened for the 2024-25 academic season.

The below graphic illustrates the morning delay comparison for a school in Montogomery County between the week prior to return to school and the first week of the new school year in Montogomery County. The chart is set for 5-minute granularity, on school days of the week between 7 and 8 a.m. (classes start at 7:45 a.m.).

ClearGuide Signal Trends can produce many different reports, including a ranked list of the intersections with the biggest change in delay. In Montgomery County, after the start of the new school season the top ranked intersections with the biggest increase in delay are all near schools.

Three of the top ten, including the very top ranked in highest delay, are locations around Wootton High School:

Ranking fifth and seventh are locations near another school:

Similarly, the location ranked sixth in delay is near a school:

The eight ranked location is near a school:

And so on. In fact, a review of the top 40 locations for delay increase at intersections reveals that all are close to schools. Using ClearGuide to see the detailed impact of schools back in session on your signal timings helps prepare and adjust for back to school congestion levels, as well as mitigate safety issues resulting from increased pedestrian traffic at these locations. Download our tip sheet on keeping school-aged pedestrians safe here.