Unbuckled and unprotected: The deadly cost of no seatbelt law in New Hampshire.

BACKGROUND: Motor vehicle crashes (MVCs) continue to be a leading cause of death in the United States, although broad adoption of seatbelt use has markedly reduced fatality. New Hampshire remains the only state without a mandatory adult seatbelt law and has the lowest seatbelt usage rate at 78%, compared with the national average of 91%. This study investigates the association between seatbelt legislation and unrestrained MVC fatalities, focusing specifically on crashes occurring in New Hampshire and occupants with New Hampshire driver's licenses. METHODS: This retrospective cross-sectional study analyzed all fatal MVCs in the United States from 2017 to 2023 using the National Highway Traffic Safety Administration's Fatality Analysis Reporting System data. The primary outcome was unrestrained MVC mortality. Exposures included crash state and state driver's license, categorized into New Hampshire, primary enforcement states, and secondary enforcement states. Multivariable logistic regression was adjusted for demographic, environmental, vehicle, and driver-related factors. Secondary analyses evaluated New Hampshire-licensed drivers outside the state and non-New Hampshire-licensed occupants within New Hampshire. RESULTS: Among 146,655 fatal MVCs eligible for analysis, 474 occurred in New Hampshire and 485 involved New Hampshire license holders. The proportion of unrestrained fatal MVCs was highest for MVCs geographically within New Hampshire (71.5%) and for occupants with New Hampshire driver's licenses (68.7%). MVCs in New Hampshire (OR, 2.80; 95% CI, 2.15-3.65) and possessing a New Hampshire license (OR, 2.74; 95% CI, 2.13-3.52) were significantly associated with increased odds of unrestrained MVC fatality. Notably, New Hampshire-licensed drivers exhibited increased unrestrained fatality risk even when traveling outside their home state (OR, 2.06; 95% CI, 1.28-3.33). CONCLUSIONS: Our findings underscore the strong association between New Hampshire's absence of an adult seatbelt law and elevated unrestrained MVC fatality risk. These data highlight the urgent need for policy interventions to enhance occupant safety through mandatory seatbelt legislation in New Hampshire. ( J Trauma Acute Care Surg . 2026;101: 80-88. Copyright © 2026 Wolters Kluwer Health, Inc. All rights reserved.). LEVEL OF EVIDENCE: Level IV.

Duke Scholars

Author Suresh Kumar Agarwal Jr. Trauma, Acute, and Critical Care Surgery

Author Krista Lynn Haines Trauma, Acute, and Critical Care Surgery

Author Scott Farrell Gallagher Trauma, Acute, and Critical Care Surgery