A recommended specification for heavy vehicle rear underrun guards

Area of Science:

• Road safety engineering
• Vehicle safety standards
• Crashworthiness research

Background:

• Underrun accidents involving heavy vehicles pose a significant risk of passenger injury.
• Existing underrun guard standards, such as U.S. FMVSS 223, were evaluated for their protective capabilities.
• A need exists for enhanced underrun guard performance to mitigate injuries in diverse vehicle types.

Purpose of the Study:

• To evaluate the effectiveness of various heavy vehicle rear underrun guard designs.
• To develop a recommended underrun guard specification based on empirical test data.
• To identify performance limitations of current underrun guard regulations.

Main Methods:

• Conducted a comprehensive research program involving static and full-scale crash tests.
• Utilized four distinct underrun guard designs during crash testing.
• Impacted underrun guards with sub-compact, compact vehicles, and light trucks/vans at relative speeds of 48, 56, and 65 km/h.

Main Results:

• Crash test data revealed that underrun guards meeting minimum U.S. FMVSS 223 requirements may be insufficient.
• Passenger compartment intrusion was observed, particularly in smaller vehicle models (sub-compact and compact cars).
• Performance varied significantly across different underrun guard designs and impact speeds.

Conclusions:

• A revised or enhanced underrun guard specification is necessary for improved passenger safety.
• Current minimum standards may not adequately protect occupants of smaller vehicles in underrun collisions.
• The study provides a data-driven basis for developing more effective rear underrun protection systems.