Write Up:

Motorists want to travel through work zones with as little inconvenience as possible. MoDOT minimizes travel impacts by shifting work times to impact fewer travelers, using technology in work zones to provide valuable information to customers and 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.

Through the third quarter of 2023, MoDOT has monitored 570 work zones consisting of 1,310 delays of 10 minutes or longer with a total congestion of 545 hours. Increased traffic volumes continue to cause higher delay and congestion trends since 2020. When comparing YTD 2023 with YTD 2022, there is a 48% increase in the number of delays and a 23% overall congestion increase.

This quarter, bridge construction on I-44, intersection work on MO 60/MO 125 and bridge work on I-55 in SL were the largest contributing projects, causing 46 hours, 33 hours and 42 hours of congestion, respectively. These projects have contributed a total of 121 hours, or 61%, of the 200 hours of congestion this quarter. For the year, bridge improvement projects continue to be the largest contributor of delays at 79%.  

The cumulative work zone congestion target is 396 hours which is an average of the congestion from 2022-2023. This target will be reevaluated in 2024.

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.