North Dakota Bridge Infrastructure: A Complete Analysis

North Dakota is home to 4,250 bridges spanning 53 counties, making it one of the most significant bridge inventories in the country. These bridges carry a combined 4,130,597 vehicle crossings every day. Here is a comprehensive look at the state of North Dakota's bridge infrastructure based on the latest National Bridge Inventory data.

North Dakota earns an overall infrastructure grade of D based on the percentage of its bridges in poor condition. Currently, 470 bridges (11.1%) are rated poor, compared to the national average of 6.7%. The average bridge in North Dakota is 49 years old, older than the national average of 48 years.

Of the state's 4,250 bridges, 1,782 are in good condition, 1,998 are fair, and 470 are poor. View the full breakdown on the [North Dakota report card](/reports/north-dakota).

These are the bridges carrying the highest daily traffic volumes across North Dakota. High-traffic bridges are critical infrastructure -- their condition directly affects the commutes of tens of thousands of drivers.

The following bridges have the lowest sufficiency ratings in North Dakota. These structures are the most likely candidates for federal repair or replacement funding under the Bipartisan Infrastructure Law.

North Dakota's oldest bridges tell the story of the state's transportation history. Some of these structures have been in continuous service for over a century.

North Dakota's bridge infrastructure grade of D reflects both the current condition of the state's bridges and the scale of the challenge ahead. With an average bridge age of 49 years, many of these structures are approaching or past the 50-75 year design life typical of most bridges. The state's ability to maintain and replace aging bridges will determine whether conditions improve or deteriorate in the coming decade.

For county-by-county breakdowns, historical trends, and individual bridge profiles, visit the [North Dakota state page](/bridges/north-dakota) or the [North Dakota report card](/reports/north-dakota). You can also explore how North Dakota compares to other states in our [state rankings](/blog/best-bridge-infrastructure-by-state-2025).