An recent analysis published in Governing found that local bridges are more likely to be structurally deficient than state bridges.

A Governing review of Federal Highway Administration inspection data found a stark disparity in the condition of local bridges compared to those owned by states. According to federal data, bridges under local jurisdiction are more than twice as likely to be considered structurally deficient, suffering from deterioration to at least one major component, such as the bridge deck or substructure.

Some of these bridges – most of which counties own – are not heavily trafficked.  And while states work with only limited funding for bridge repairs, municipalities possess even fewer resources. It’s for these reasons, experts say, that bridges localities own typically fall low on the list for priority repairs.

Limited funding tends to be the reason local bridges are not as structurally sound.

The disparity in bridge conditions largely hinges on funding, said Bob Fogel, senior legislative director for the National Association of Counties.Local governments typically lean heavily on real estate taxes for general fund revenues. Smaller or rural counties don’t have expansive enough tax bases to pay for upgrades. And urban localities often need permission to levy taxes funding transportation projects from both state governments and taxpayers – a major hurdle.

A smaller share of bridge funding trickles down from states and the federal government, varying greatly from system to system. Michigan, for example, distributes a portion of gas tax revenues to cities and counties, some of which is set aside for its Local Bridge Program. Other states also share fuel or motor vehicles taxes with localities, but even this added money doesn’t begin to cover all the costs.