Review and Analysis of Potential Safety Impacts of and Regulatory Barriers to Fuel Efficiency Technologies and Alternative Fuels in Medium- and Heavy-Duty Vehicles

This report summarizes a safety analysis of medium- and heavy-duty vehicles (MD/HDVs) equipped with fuel efficiency (FE) technologies and/or using alternative fuels (natural gas-CNG and LNG, propane, biodiesel and power train electrification). The study included a comprehensive literature review, complemented with inputs from subject matter experts (SMEs), and a scenario-based hazard analysis. Specific FE technologies examined include: Intelligent Transportation Systems (ITS) and telematics, speed limiters, idle reduction devices, tire technologies (single-wide tires, tire pressure monitoring systems-TPMS and Automated Tire Inflation Systems-ATIS), aerodynamic components, long combination vehicles (LCVs) and lightweighting materials. Federal and State safety regulations, and voluntary technical standards affecting MD/HDV fleet adoption of FE technologies and alternative fuels were discussed, and potential regulatory barriers identified. The findings suggest that the potential safety hazards identified can be prevented or mitigated by complying with safety regulations and voluntary standards and industry best practices. The study did not identify any major regulatory barriers to rapid adoption of FE technologies and alternative fuels by the MD/HDV fleet.