Write Up:

The public has indicated that keeping Missouri’s existing roads and bridges in good condition should be one of the state’s highest priorities. The Fixing Americas Surface Transportation Act established a 10% penalty threshold for states that, when exceeded, requires a state to focus money on bridges until they are back under 10%. The local system has 83 National Highway System structures (three structurally deficient) and the MoDOT system has 3,569 NHS structures (163 structurally deficient). Missouri currently falls below the penalty threshold with the statewide structurally deficient deck area at 8.2%. This is attributable to the continued effort to focus on major bridges when funding is available as well as increasing focus on condition bridges in the STIP.

Statewide, this measure is also heavily influenced by major bridges with one structure having the ability to impact this measure +/-0.5%. From 2017 to 2018, there was an increase in the statewide percentage of structurally deficient deck area on the NHS due to the addition of five major bridges representing 1.4% of the total NHS deck area. The number of bridges on the NHS has stabilized with very small changes from year to year. Ohio has been selected for comparison because it has similar demographics, geography and weather conditions. There are 10,427 total state highway bridges in Ohio with 4,855 structures on the NHS.

Purpose of the Measure:

This measure tracks the percent of structurally deficient deck area for bridges on the NHS.

Measurement and Data Collection:

The NHS is defined by federal law and consists of all roadways functionally classified as principal arterials as well as some routes that serve as major connections to multimodal freight-type facilities and some locally owned roadways. FAST Act requires states to track the structurally deficient deck area on the NHS. Historically, the term structurally deficient defined a group of bridges that were in bad condition or had insufficient load capacity when compared to modern design standards. With the implementation of the FAST Act, this definition has changed and this measure reflects those changes. The FAST Act has a penalty threshold that requires a state to take certain actions whenever the percentage of structurally deficient deck area within a state exceeds 10 percent. The chart reflects keeping the percentage below 10 percent as the target.