Powering The Fridge Underway

We had a great, but short, trip last month, Phoenix to Durango and back. The real objective of the trip was to learn about RV travel first hand. We're going to rent a few models of the R-Pod before we decide on buying. That's where we are.

On the trip we had issues with keeping the fridge cold while traveling. Never did solve it. Seems to be a difference in opinions about using battery power or propane power while on the highway. What is correct? One person tells us, kinda in low tones like it was a dirty little secret, "Keep the propane cracked open a little to get to the fridge, but don't let any law enforcement people know!".
Huh?
Another person had the opposite opinion. "OMG!! Don't EVER do that!"
And another.... "Yes, it's best to use propane anytime you are not hooked up to power. And yes, that includes while traveling on the highway.

So... forgive me if this is one of those "Newby" questions. We are total newbies and appreciate the valuable experience living on the forum.

What are the best/rightest/smartest things to do?

I use propane when on the road all the time.  The only time you need to turn it off is when you pull in to a gas station to refuel.  The new style propane tanks have safety shutoff valves inside the tank so if there was a huge gas leak it would automatically shut off.  The tiny flame that the refrigerator uses inside of the combustion area really poses no threat of burning down your RV.

Sometimes you do see a burned out camper. Saw this one on our last camping trip, but don't know how it started. Very scary looking. Glad we weren't camping near it when it happened.

They put gas water heaters in garages, mounted above the floor because gasoline vapors are heavier than air and so sink to the floor.

The National Fuel Gas Code (Z 223.1 – 2006, Section 9.1.10.1)
Installation in Residential Garages
a. Appliances in residential garages and in adjacent spaces that open to the garage and are not part of the living space of a dwelling unit shall be installed so that all burners and burner ignition devices are located not less than 18 in. (460mm) above the floor unless listed as Flammable Vapor Ignition Resistant.

The only restrictions I've read about with operating propane on the highways is in tunnels. (all back on the East cost and Texas)
GENERAL COMMENTS:
Tunnels that go down hill have restrictions to stop and make sure propane is turned off. Tunnels that rise slightly have no restrictions.
Virginia tunnels go down under the water. Propane is heavier than air and in theory could pool in the very bottom of the tunnels. So you need to stop and tell an inspector they are turned off.
Most tunnels that go thru mountains have a slight rise to the middle. That's why you don't have to stop for most of those tunnels.
http://www.rvtripwizard.com/rv-info/propane-tanks-in-tunnels.html

Originally posted by JandL They put gas water heaters in garages, mounted above the floor because gasoline vapors are heavier than air and so sink to the floor. The National Fuel Gas Code (Z 223.1 – 2006, Section 9.1.10.1) Installation in Residential Garages a. Appliances in residential garages and in adjacent spaces that open to the garage and are not part of the living space of a dwelling unit shall be installed so that all burners and burner ignition devices are located not less than 18 in. (460mm) above the floor unless listed as Flammable Vapor Ignition Resistant. The only restrictions I've read about with operating propane on the highways is in tunnels. (all back on the East cost and Texas) GENERAL COMMENTS: Tunnels that go down hill have restrictions to stop and make sure propane is turned off. Tunnels that rise slightly have no restrictions. Virginia tunnels go down under the water. Propane is heavier than air and in theory could pool in the very bottom of the tunnels. So you need to stop and tell an inspector they are turned off. Most tunnels that go thru mountains have a slight rise to the middle. That's why you don't have to stop for most of those tunnels. http://www.rvtripwizard.com/rv-info/propane-tanks-in-tunnels.html

Fascinating post. The part about garage heaters confirms what Techntrek's been saying for years. Gasoline fumes are heavier than air and tend to stay low. The part about tunnels East and West also interesting. I never stopped to think about going under rivers vs going up through mountains. Of course we all know Propane pools in basements  and can be ignited by sparks or matches

I travel with the fridge on Propane with no concerns, but my 7 cu fridge gives me no other option.