About Missouri’s Bridges
MoDOT is responsible for maintaining nearly 10,400 bridges on the state system. The average age of our bridges is 48 years and most of them were designed to last 50 years. Sixty percent of Missouri’s bridges are beyond their original intended life.
We currently have 909 bridges that have been rated “poor” by the Federal Highway Administration. Each year about 100 bridges fall into the “poor” category, and we fix or replace about 90. The number of poor bridges in Missouri is rising steadily as we struggle to hold our own.
Bridges are rated on a nine-point scale, with 9 being a new bridge and 2 being a closed bridge. Missouri’s poor bridges carry a rating of 4 or less.
This situation is symptomatic of where we are. We have the nation’s 7th largest system of roads and bridges but our funding comes in at 48th in the nation. We can only stretch our dollars so far, and must prioritize our work.
A Thorough Inspection Process
All bridges are inspected regularly in accordance with federal law, typically every two years. If a bridge has known problems, it is inspected more frequently. If a bridge is open to traffic it is safe; however, as our bridges age and deteriorate, we are having to close them more often.
There are 1,131 of our bridges that are weight restricted which means they are unable to carry some normal traffic. Examples of what some common vehicles weigh are shown in the graphic here.
Condition Ratings and Common Bridge Terms
What exactly do we mean when we say bridges are “poor” and “weight restricted?” Click on the link below to learn more about condition ratings and bridge terms.