I’ve spent a lifetime repeatedly learning that I don’t know everything.
Insatiable curiosity, and a rather diverse career, have led me down some deep rabbit holes. In writing and speaking about hydrogen fuel cell trucks for NACFE I brought up some new challenges the nascent industry and society may not yet fully grasp. Chief among them being that we largely have not yet thought about integrating hydrogen fuel cell trucks into the nation’s transportation network. Simply put, can you legally drive a fuel cell truck everywhere? And that invariably is followed by the question, “Should you be able to drive a fuel cell truck everywhere?”
New technologies like hydrogen, battery electric and autonomous vehicles bring with them unknowns. As we boldly go where no technology has gone before we are likely to need to flesh out some details. Lack of guidance and regulation does not necessarily mean they are not needed.
Turns out that figuring out if hydrogen trucks can and should operate everywhere is a tough question to answer today. According to Colorado regulations, for example, you cannot drive a hazmat commercial vehicle through the Eisenhower Tunnel. In Maryland, it may be illegal to drive a hydrogen powered truck on the Chesapeake Bridge Tunnel. New York and New Jersey have a whole raft of tunnels and bridges with various restrictions. British Columbia ferries have no mention of “hydrogen” per se, but while they permit some gasses, commercial vehicles may not be allowed to transport propane. As I said, I’m not an expert, just a curious researcher with access to web search engines.
According to various Material Data Safety Sheets, (MSDS) and United Nations Committee of Experts on the Transport of Dangerous Goods UN 1049 and the U.S. Department of Transportation Code of Federal Regulations 49 CFR §172, it appears commercial compressed hydrogen is a Hazard Class 2.1 substance described as a flammable gas. That seems clear enough, but does a vehicle operating on hydrogen contain enough hydrogen to be so designated? My guess is that that will have many answers depending on who and where you ask.
Some of the codes I found appear to limit alternative fuel sizes for natural gas and propane. For example, in Maryland the limit is to below 150 lbs. (68 kg) on-board to be a qualified alternative fuel vehicle, but then rules limit tunnel transit tanks to below 10 lbs. (4.5 kg) per container. NACFE’s hydrogen reports highlighted that hydrogen capacity for proposed fuel cell trucks might be 50 to 80 kg (110 lbs. to 176 lbs.) to achieve longer ranges of 350 to 600 or more miles.
The U.S. Federal Motor Carrier Safety Administration (FMCSA) has a map tool showing designated hazmat routes in each state. A brief sampling of states seems to identify a small number of key tunnels and bridges as having hazmat restrictions.
