Always on when driving..shut off when taking a ferry , but have never shut off in a tunnel...and dont think anyone would stop and turn off before a tunnel. Even the tunnel between Windsor and Detriot have never seen anyone shutting off plus there is no room to stop and do it on either side.
If there was a problem and a hose did rupture , the valve on the tank will automatically shut down.
It was a rainy few days at Algonquin Prov park...tarps kept us dry.
Wayne --Belle River (Windsor), Ontario
2013 Sunset Trail Reserve 25RB..
2015 White Chev Silverado 2500HD 4x4 (6.0 l gasser)
2003 Mountain Star 890SBRX Truck Camper