Most RV GPS units and route planning apps don’t account for propane restrictions on tunnels and certain highways, which can leave you scrambling for detours at the worst possible moment. Many major routes — particularly in the Northeast and around major cities — have tunnels that prohibit vehicles carrying propane tanks, even the standard tanks mounted on travel trailers and motorhomes.
The challenge is that these restrictions aren’t consistently marked in navigation databases. You might get routed through the Holland Tunnel or Baltimore Harbor Tunnel only to discover at the entrance that RVs with propane must take a completely different route that adds an hour or more to your trip. Some restrictions are seasonal, others depend on tank size, and a few have exemptions for built-in tanks versus portable ones.
Experienced RVers solve this by cross-referencing their planned route with state DOT websites before departure, particularly when traveling through New York, New Jersey, Maryland, and California. Many keep a printed list of known propane-restricted tunnels in their route planning folder. The most reliable backup strategy is identifying alternate routes in advance rather than trying to figure out detours while sitting in traffic approaching a tunnel entrance.
Some newer RV-specific GPS units are getting better at flagging these restrictions, but the databases still aren’t complete. When in doubt, calling ahead to state transportation departments can save hours of unexpected detours, especially on routes you haven’t traveled before.