Write Up:

Understanding how long it takes to clear roads after a winter storm helps MoDOT analyze costs and improve efficiency. The department’s response to winter events ensures good customer service for travelers while keeping expenses as low as possible. These efforts reduce delays and, most importantly, promote safer travel. In recent years, MoDOT has increased public messaging urging drivers to travel only when necessary, during winter storms. This cooperation helps crews manage roadways more effectively and improves clearance times.

Staffing challenges have impacted operations. In recent seasons, MoDOT’s Maintenance Division has been short by several hundred employees. While staffing has improved over the past two years, it remains below the level needed to keep all plow trucks running for consecutive 12-hour shifts. This shortage, combined with previously mild winters, has resulted in less experienced operators and many drivers still completing on-the-job training before operating  plow trucks independently.

Weather severity also affects performance. MoDOT uses a Winter Severity Index (WSI) to compare each season to a typical Missouri winter. A WSI of 1 indicates normal conditions; values above or below 1 reflect more or less severe winters. For the 2025–2026 season, there were seven statewide events, and even though a couple of those events were significant—with an individual WSI above 1—the overall season was mild, with a WSI of 0.8. Compared to previous seasons, this season was about 40% less severe than last year and slightly more severe than the 2023 and 2024 seasons. Clearance times on continuous routes decreased (improved) by about 30% compared to last season and by about 20% compared to the 2023 and 2024 seasons. Clearance times on non-continuous routes improved by 50% compared to the previous  three seasons.

Over the past five years, winter operations have averaged $49.8 million annually. The cost for the 2025–2026 season was $ 43.8 million, which was lower than the cost for the 2023–2024 season, despite having a similar weather severity index.

Purpose of the Measure:

This measure tracks the time required to complete MoDOT’s snow and ice removal efforts. It also evaluates the impact of significant events and the actions taken to minimize those impacts.

Measurement and Data Collection:

To determine the magnitude of a winter event’s impact on the traveling public and MoDOT, a Winter Severity Index (WSI) is calculated using data collected from multiple sources. This data is centralized in a web-based integration and analytics platform that processes the information and provides interactive visualizations to help users identify trends.

Data sources for this tool include MoDOT’s TMS and MMS systems, the Regional Integrated Transportation Information System (RITIS), Road Weather Information System (RWIS), Missouri Automated Surface Observation System (ASOS), HERE Traffic Analytics, Missouri State Highway Patrol, and the National Weather Service.