The Stop Underrides Act 2.0 is a safety bill designed to prevent deaths and injuries from underride crashes—when smaller vehicles or motorcycles slide underneath large trucks or trailers during collisions. The bill addresses a serious public health crisis: since the National Highway Traffic Safety Administration was created over 50 years ago, more than 25,000 underride crashes have killed approximately 31,500 people, with little progress made to prevent them.

The bill requires the Department of Transportation to create new safety standards for protective guards on trucks and trailers. Specifically, it mandates side underride guards on new trailers, semitrailers, and single-unit trucks that can prevent smaller vehicles from sliding underneath at speeds up to 40 miles per hour. The regulations must be finalized within 18 months, with full compliance required within 2 years after that. The bill also requires the DOT to study front-end underride crashes (which are less regulated) and to review how well existing rear-guard standards are working.

Beyond the technical requirements, the bill establishes a public website where researchers, safety advocates, and the public can access underride crash data and research. It reactivates and expands an advisory committee of experts and victim families to meet regularly and provide guidance. The bill also requires training for police officers to properly identify and document underride crashes, since many are currently misreported or not recognized as underride incidents. Every five years, the DOT must review whether the safety standards need updating based on new evidence.