ST. LOUIS – Despite being the 18th most populous state in the country, Missouri has the seventh-largest system of roads and bridges in the nation.
Whether it’s transporting goods and livestock, traveling on vacation, or driving to and from work or other destinations, our roads and bridges are critical infrastructure.
Following the collapse of the Interstate 95 overpass in Philadelphia earlier this month, we examined the conditional status of bridges in the Show Me State to see which ones need to be repaired or replaced.
But like a lot of things in this world, the answer depends on who you ask.
The Missouri Department of Transportation maintains 10,387 bridges across the state. The average age of those bridges is 48 years. Most of those bridges were designed to last a half-century. Approximately 53% of bridges that MoDOT is responsible for are past their intended use.
Despite that, just 823 bridges in the MoDOT system (7.9%) are rated as “poor” under the Federal Highway Administration standard. More than 6,500 are rated “fair” and the remaining 3,000-plus bridges are in “good” condition.
MoDOT conducts safety inspects all of its bridges, about every two years. For each bridge, engineers examine its deck, superstructure, and substructure, and rate each component on a 9-point scale, with 9 being excellent and 0 meaning that the component has failed.
The lowest rating of all three components is used as the overall rating of the bridge. A rating of 7 and up is classified as Good, 5 or 6 is considered Fair, and bridges rated 4 and under are classified Poor. If a bridge has an overall rating of 2, it is closed.
You can view a map of all the bridges rated poor, including an inset of the St. Louis area (seen above), and read the full list of poor and weight restricted bridges at MoDOT.org. Twenty-six of those bridges are located in St. Louis City and County.
But MoDOT does not maintain every bridge in the state.
Data from the Federal Highway Administration (FHWA) and the National Bridge Inventory (NBI) shows Missouri has 24,569 bridges, of which 4,595 bridges are in need of repair.
The American Road & Transportation Builders Association, citing data from both organizations, says 2,230 bridges are rated poor, and 2,560 bridges need to to be replaced entirely. More than half of the poor-rated bridges are on “rural local roads,” according to the ARTBA report.
According to the NBI, six of the 10 most-traveled poor-rated bridges in Missouri are all located in St. Louis City and County.