New Hampshire Bridges

New Hampshire maintains 2,542 highway bridges across 10 counties, forming critical links in the state's transportation network. With an average construction year of 1968, the typical bridge in New Hampshire is approximately 58 years old—9 years older than the national average of 49 years. The state's oldest bridge dates back to 1832, representing over a century of service and offering a window into historic bridge engineering practices.

Currently, 7.5% of New Hampshire's bridges are rated in poor condition, exceeding the national average of 6.8%. This highlights infrastructure challenges that transportation agencies are working to address through maintenance, rehabilitation, and replacement programs. A "poor" condition rating indicates significant deterioration requiring attention, though these bridges remain safe for travel at their posted limits. Federal regulations require bridge inspections at least every 24 months to ensure public safety.

Bridge conditions in New Hampshire reflect decades of infrastructure investment decisions shaped by geography, climate, traffic demands, and available funding. Average daily traffic of 6,725 vehicles per bridge is below the national average, which can reduce wear but still requires consistent maintenance investment. The state's 17,054,577 total daily bridge crossings underscore how essential this infrastructure is to daily commerce and commuting.

The material composition of New Hampshire's bridge inventory reflects regional construction practices and evolving engineering standards. The predominant construction material is steel, accounting for 54.1% of all structures. Material choice affects maintenance requirements, expected lifespan, and vulnerability to environmental factors specific to the region. Understanding these patterns helps transportation planners allocate resources effectively and prioritize infrastructure investments.