DOT envisions hydrogen as a near- or mid-term alternative fuel by commercial vehicles in two ways:  (1) auxiliary power (i.e., refrigeration, lighting, and climate control) to avoid diesel idling and (2) propulsion power in local, urban delivery trucks.  DOT does not envision utilization of hydrogen for long-haul trucks at this time because the energy density of hydrogen does not favor hydrogen as a replacement for diesel fuel in such operations. 

The changes that DOT envisions are necessary to accommodate hydrogen as an alternative fuel in commercial vehicles follow:

·        Dissemination of general safety guidelines for hydrogen fuel systems in commercial vehicles.  At present, there are no such guidelines to assist commercial vehicle owner/operators.  Thus, the guidelines are intended to assist fleet managers who supervise drivers on the road as well as operations and maintenance personnel at fleet terminals.  The guidelines are NOT intended as in-depth specifications for Original Equipment Manufacturers (OEM) to design and build hydrogen systems.   

·        Revisions to the Federal Motor Carrier Safety Regulations (FMCSRs) that cover, in particular, fuel systems, fueling, and wiring on commercial vehicles.  The revisions are based on the need to address (i) hazards associated with the forms of on-board hydrogen storage and (ii) properties of hydrogen that differ from conventional diesel fuel.  

·        Revisions to the North American Standard (NAS) Levels I, II, V, and VI inspection procedures for commercial vehicles based on revisions to the FMCSRs.

·        Revisions to the North American Standard Out-of-Service Criteria for removing a commercial vehicle from operating on public roads as the result of following NAS inspection procedures.