New Hampshire Bridge Infrastructure: A Complete Analysis

New Hampshire is home to 2,549 bridges spanning 10 counties, making it one of the most significant bridge inventories in the country. These bridges carry a combined 17,359,761 vehicle crossings every day. Here is a comprehensive look at the state of New Hampshire's bridge infrastructure based on the latest National Bridge Inventory data.

New Hampshire earns an overall infrastructure grade of C based on the percentage of its bridges in poor condition. Currently, 192 bridges (7.5%) are rated poor, compared to the national average of 6.7%. The average bridge in New Hampshire is 58 years old, older than the national average of 48 years.

Of the state's 2,549 bridges, 1,303 are in good condition, 1,054 are fair, and 192 are poor. View the full breakdown on the [New Hampshire report card](/reports/new-hampshire).

These are the bridges carrying the highest daily traffic volumes across New Hampshire. 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 New Hampshire. These structures are the most likely candidates for federal repair or replacement funding under the Bipartisan Infrastructure Law.

New Hampshire'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.

New Hampshire's bridge infrastructure grade of C reflects both the current condition of the state's bridges and the scale of the challenge ahead. With an average bridge age of 58 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 [New Hampshire state page](/bridges/new-hampshire) or the [New Hampshire report card](/reports/new-hampshire). You can also explore how New Hampshire compares to other states in our [state rankings](/blog/best-bridge-infrastructure-by-state-2025).