Community Forums

Kwayzhar · 07-20-2012, 07:27 AM

For vertical clearances on US roads I read in Wikipedia " Minimum vertical clearance under overhead structures (including over the paved shoulders) of 16 feet (4.88 m) in rural areas and 14 feet (4.27 m) in urban areas, with allowance for extra layers of pavement."

There's an overpass near my house at 13'6"... buses and 18-wheelers fit under just fine it seems.

When I eventually obtain my DP, what kind of typical height should I expect and how frequent a concern are underpasses?

pumper9x9 · 07-20-2012, 08:09 AM

The minimum height on the signs is suppose to be at the edge of the road. I measured the highest solid point on my rig and added 6" just to be safe. I have a flexible CB antenna that sticks up a couple of inches above my satellite dish that kind of acts like a vertical curb feeler. You'll have to pay attention to height warning signs as you drive, Another alternative is to get a truckers map or the GPS and they should have all the routes that have a minimum 13'6" clearance. We are in Charlottesville now and saw a semi truck stopped short of a bridge with 10' clearance. He was going to have a hell of a long way to back up in traffic to get out of that situation. If you find yourself in a pickle like that give the local cops a call and see if you can get them to help you get out of there.

Kwayzhar · 07-20-2012, 08:22 AM

Quote:

Originally Posted by pumper9x9

The minimum height on the signs is suppose to be at the edge of the road. I measured the highest solid point on my rig and added 6" just to be safe. I have a flexible CB antenna that sticks up a couple of inches above my satellite dish that kind of acts like a vertical curb feeler. You'll have to pay attention to height warning signs as you drive, Another alternative is to get a truckers map or the GPS and they should have all the routes that have a minimum 13'6" clearance. We are in Charlottesville now and saw a semi truck stopped short of a bridge with 10' clearance. He was going to have a hell of a long way to back up in traffic to get out of that situation. If you find yourself in a pickle like that give the local cops a call and see if you can get them to help you get out of there.

Vertical feeler

I'm all for attentiveness... I'm thinking a GPS alert would work great as a backup.

I suppose typical rig height is kinda vague considering it probably varies quite a bit. Thanks for the tips!

topdownman · 07-20-2012, 08:31 AM

You'll love these:

The Good, The Bad and Some Ugly Crashes - YouTube

RickO · 07-20-2012, 08:31 AM

My 40DP is just over 12'.

Vertical clearance isn't something that's caused me much concern.

Rick

Kwayzhar · 07-20-2012, 08:52 AM

Quote:

Originally Posted by topdownman

You'll love these:

The Good, The Bad and Some Ugly Crashes - YouTube

"Content owner has made this video unavailabe on mobile"

Doh!! I'll have check em out later. I've seen some before... it's not pretty. My advice; don't fight physics

wa8yxm · 07-20-2012, 09:20 AM

The maximum allowed height for ANY vehicle without a permit is 13'6" I seem to recall reading a lower max for motor homes but have been unable to re-locat it so wont' mention the number save to say it's the height of MY rig.

Do the following.
You need

1 Buliding you can park next to at least 14" tall at the eve.

A laser level
A friend
A laddar ((or 2))
a tape measure

Take the laser level (And one ladder, may be attached to RV) and get up on the roof, locate the higest point and lay the laser level on that, activate and "paint" the building wall with the red dot of the laser. (make sure level is .. Well. Level)

Have friend put a pencil mark where the dot hits the wall

Meassure height of pencile mark with tape measure.

Now you know height of rig, as someone said, add six inches.

Kwayzhar · 07-20-2012, 09:28 AM

Wa8yxm,

Thanks. Good tip. High precision...

Most rigs should include this spec, ya? In the manual or on dataplate?

- K

Kwayzhar · 07-20-2012, 09:30 AM

Quote:

Originally Posted by RickO

My 40DP is just over 12'.

Vertical clearance isn't something that's caused me much concern.

Rick

Thanks... that's reassuring

- K

Fred1609 · 07-20-2012, 09:34 AM

DW bought a program on the internet which loads into the GPS unit and rings when you are approaching an overpass which is under the height of your rig that you've programed into the GPS.

W4MBG · 07-20-2012, 09:39 AM

measure the height from the ground to the edge of the roof of the rv. assuming a flat roof, get up top and measure from the roof to the top of the a/c unit (or whatever is the tallest thing up there). add the two numbers together. add in a safety factor of your liking. done.

the biggie is having a flat roof.

demoon · 07-20-2012, 09:47 AM

Please don't trust your GPS for height restrictions any more than you do for other things. They can be wrong. As I have posted before, my Rand 5510 (smaller brother of 7710) tried to take us under a bridge that was posted for 10' 6" and I have the height set for 12'.

Wayne M · 07-20-2012, 10:04 AM

If you don't have an object to park next to, you can use the laser level and tape measure by, and do it alone but it is easier to have a friend along. Place the laser level on the highest point of the RV and make sure it is level. Find the laser level dot. You can do this with your body. Just remember not to walk backwards to the edge. Extend the tape to the ground holding on to the rewind/spring portion. Look at where the laser dot hits the tape. That is your height.

Some things to consider. Resurfacing of the road ljust before the underpass can change the height by an inch or two. Hopefully the DOT will re-label the signs before or during re-surfacing. Snow can also cause a difference in height. Spilled debris such as gravel, sand, etc can cause a temporary difference in height. Other items of mechanical nature on the RV/Truck can affect overall height such as tire air pressure, air bag pressure, etc., so when measuring make sure things are as you will be traveling.

So ensure you have a fudge factor of a couple inches and in those situations that you are not sure about wait for an 18 wheeler to come through with a box on the tractor. To the top of the box is 13' 6" when I asked an 18 wheel driver.

Happy trails.

Kwayzhar · 07-20-2012, 10:20 AM

Quote:

Originally Posted by demoon

Please don't trust your GPS for height restrictions any more than you do for other things. They can be wrong. As I have posted before, my Rand 5510 (smaller brother of 7710) tried to take us under a bridge that was posted for 10' 6" and I have the height set for 12'.

Agreed. Situational awareness/attentiveness is the key. GPS warnings are just an additional red flag I'd say. That is, audible warnings are helpful, but blind trust when it says "good to go!" is bad.