Write Up:

Motorists want to travel through work zones with as little inconvenience as possible. MoDOT tries to minimize travel impacts by shifting work times to impact fewer travelers, by using technology in work zones that provides valuable information to customers and by using innovative traffic control devices to promote efficient traffic flow. To measure the effectiveness of these strategies, MoDOT monitors the performance of work zones with the greatest potential to impact traffic each quarter. The goal is to minimize the number of times a work zone creates a traffic delay of 10 minutes or more.

Although 2023 showed the highest number of delays and overall congestion as compared to the previous five years, 2024 is trending lower for both number of delays and overall congestion. When comparing year-to-date 2024 with YTD 2023, there is a 26% decrease in the number of delays and an 18% overall congestion decrease. MoDOT has monitored 501 work zones consisting of 1,039 work zone delays of at least 10 minutes and total congestion of 446 hours.

This quarter, pavement reconstruction on I-55 in Southeast District (Pemiscot), on US-54 in Central District (Callaway) and bridge work on I-270 in St. Louis were the biggest three contributing projects, causing 20 hours, 15 hours, and 12 hours of congestion, respectively. These projects have contributed a total of 57 hours of the 139 hours (41%) of congestion this quarter. For the year, bridge improvement projects continue to be the largest contributor of delays at 63%.

The target for the cumulative work zone congestion statewide was set at 557, an average of the completed previous three years of data. This will remain a rolling 3-year average. The average is based on data from 2021-2023 calendar year.

Purpose of the Measure:

Work zones are designed to allow the public to travel through them safely and with minimal disruptions. This measure tracks the performance of significant work zones.

Measurement and Data Collection:

Work zone impacts are identified using automated data collection and visual observations. An impact is defined as the additional time a work zone adds to normal travel. Impacts resulting in a delay of at least 10 minutes are included in this report. The targeted hours of work zone congestion are based on previous years' data and an acceptable tolerance of 30 total minutes for work zone congestion statewide. The target for this measure is updated quarterly.