From Amerigas.com (http://blog.amerigas.com/residential-propane/rv-propane-safety/)-
On the Road
Most RV refrigerators can keep food/beverages cold during several hours of travel without a power source. It is recommended that propane systems be turned off while driving. Other safety tips while traveling:
Shut off propane supply valves, pilot lights, ignitors, and appliances, and have everybody exit the vehicle during refueling.
Do not use range burners for heat, or any appliances for means other than their intended use.
Extinguish all smoking materials any time you are near tanks, filling stations, or other equipment where gasoline or propane may be present.
Turn off propane supply valves before entering tunnels or enclosed areas. Be sure to follow any postings around restricted areas, such as military bases.