Trailer heights and bridges?

[allstarr]

I was wondering, how does that work. I've seen bridges of various heights over the years. However, I've never really given the heights any consideration. Are all trailers a max height, to fit under all bridges? Is there some resource that lets one know how high a bridge is, so that one knows if their trailer will be able to pass, before they're on the road? Thanks.

[kaypsmith]

12 minutes ago, allstarr said:

Are all trailers a max height, to fit under all bridges? Is there some resource that lets one know how high a bridge is, so that one knows if their trailer will be able to pass, before they're on the road?

On all roads there is no guaranty that bridges will be a minimum height. Here is the requirements on an interstate.

On Interstates, the clear height of structures shall not be less than 16 feet (4.9 meters) over the entire roadway width, including the useable width of shoulder. In urban areas, the 16-foot (4.9-meter) clearance shall apply to at least a single routing.

Most box semi trailers are 13',6", and no that is not some rule that exist, just common practice. Many atlas's will give clearances on a route. 

Currently, Google Maps does not support different vehicles types or any commercial vehicle settings. ... Many non professional drivers hit the road every year with recreational vehicles and find themselves stopped (or damaged) by an unexpected low bridge.Sep 13, 2019

It is a very good thing to research your route for both Height, weight, and width when planning a trip. Your question is a very good one and thanks for making yourself and others of thes facts.

[hermanmullins]

Also know the height of your RV.

In our small town there are two bridges that the signs on both read 14' 4". 8 miles North there is an 13' 6" and all three are on US Hwy 69, a major US Highway.

Herman 

[richard5933]

Most states do have restrictions on how tall a vehicle can be without an permit. This document lists the max height permitted, but that doesn't mean that all the bridges in the state will be that high - they won't.

https://www.rvia.org/system/files/media/file/Maximum Vehicle Height.pdf

If you look at a trucker's atlas you can find lots of information about height restrictions around the country. This atlas also shows marked truck routes, which usually means that a vehicle at or under the legal limit can fit. There are exceptions though, and it's important to watch every sign. I was driving semi last summer. On a delivery to a customer the truck route was detoured, and on the detour I encountered a bridge which looked way too low. Luckily I saw it before it was too late to turn off that road and find another route.

https://store.randmcnally.com/2021-deluxe-motor-carriers-road-atlas.html

Most GPS units aimed at RV drivers or commercial truck drivers will have a way to enter the vehicle height. I use a Garmin unit and it uses my coach's height, width, length, and weight to plan routes which are suitable. I still double check with the trucker's atlas AND I use Google Maps to drive the route virtually using Street View if there are any areas of concern. You can usually see the actual signs along the route on Street View. I've used this many times to double check bridge load limits, underpass heights, or for signs indicating 'no trucks'. The 'no trucks' signs could be for a few reasons, including weight limits, height limits, etc. so it's important to check before driving past one.

[manholt]

My Coach is 13' 4"....Lots of Interstate Hwy's that read 14' 6', US Hwy that are 13' 6" and Toll Roads (Freeways are 13' 6") !  Know before you go!

 

[wildebill308]

7 hours ago, allstarr said:

I was wondering, how does that work. I've seen bridges of various heights over the years. However, I've never really given the heights any consideration. Are all trailers a max height, to fit under all bridges? Is there some resource that lets one know how high a bridge is, so that one knows if their trailer will be able to pass, before they're on the road? Thanks.

The first thing is to know exactly how tall your RV is. Not what someone at a desk somewhere  thinks it is. You need to measure as ready to travel. This includes if you have air suspension or air booster springs. When you are headed under that low bridge is not the time to wonder "how tall am I". Keep in mind how long you are may affect your clearance if the dip in the road is fairly abrupt. 

Bill

[charlieiam]

Traveling over the USA we have beaten 4 antennas off the top of our coach hitting low bridges at highway speed.  The satellite antenna is13' high but some radio antennas are much higher.

[nessa]

AND if you are going to Canada know your height in meters.  Put a sticky note on the dash so you don't have really think about it as you drive.

[rayin]

On 4/11/2021 at 7:06 PM, nessa said:

AND if you are going to Canada know your height in meters.  Put a sticky note on the dash so you don't have really think about it as you drive.

Right! At 55kmph a driver doesn't' have time to perform these mental calculations. That's one reason why all speedometers have both scales on the  readout. Feet to Meters is the same type conversion, only much less used in daily driving. I have a small permanent placard on the dash of our MH, it states " minimum height 13 feet/ 3.1 Meters. That worked great until the caravan leader happened upon an unmarked RR underpass in Newfoundland.  ( ´△｀)

Edited April 13, 2021 by rayin

[manholt]

Ray, I think that's the same RR we found with Fantasy Tours in  2019!  With the AC Tradition at 12' 3", no problem....our friend in front of us at 13' 4" + antenna, heard it. LOL  Now we have a King Aire at 13' 4".

[rayin]

Carl one of the couples  in our S.M.A.R. T. group had a Alfa SeeYa, he and a large 5er took an alternate route to bypass that underpasss, the rest of us made it through OK. YaKnow it''s almost impossible to not duck your head in that situation, all the time knowing it doesn't help.

[wayne77590]

5'er friend of a friend went on the Merritt Parkway in CT.  Tore the roof back on the 5'er for several feet.

I like the ability to put in the RV information in the GPS but I rely more on those yellow caution signs for clearances.

[manholt]

Problem on secondary Hwy's is if the lay on a new surface, without taking the old off....you'll loose up to 6" in clearance!  

[richard5933]

When going through driver training last year for a semi driving job, the trainers would ask us what the signs said on the bridge just after we passed through the bridge. Every time. Doesn't take much to start noticing and reading every sign you pass and committing it to short term memory.

I practiced reading EVERY warning sign out loud while driving my car for a few weeks before taking my test. Good thing too, as sure enough the examiner asked about a rather hidden sign after we'd passed it.

Some of the signs to watch are not near bridges - watch for signs warning against truck traffic, warning about a truck route which ends or turns, etc. Not every warning about an upcoming problem is as clear as we'd like.

[C-677946]

On 4/14/2021 at 11:50 AM, wayne77590 said:

5'er friend of a friend went on the Merritt Parkway in CT.  Tore the roof back on the 5'er for several feet.

"Trucks, buses, trailers, towed vehicles, and all vehicles 8 feet (2.4 m) tall or taller are not allowed on any part of the parkway due to its low bridges, narrow lanes, and tight curve radii."  And in NYS, RVs are not permitted on any Parkways!

 

[C-677946]

On 4/14/2021 at 6:44 PM, richard5933 said:

When going through driver training last year for a semi driving job, the trainers would ask us what the signs said on the bridge just after we passed through the bridge. Every time. Doesn't take much to start noticing and reading every sign you pass and committing it to short term memory.

I practiced reading EVERY warning sign out loud while driving my car for a few weeks before taking my test. Good thing too, as sure enough the examiner asked about a rather hidden sign after we'd passed it.

Some of the signs to watch are not near bridges - watch for signs warning against truck traffic, warning about a truck route which ends or turns, etc. Not every warning about an upcoming problem is as clear as we'd like.

When I was a brand new semi driver, just back from Vietnam, I was on US 62  and a designated "truck route" up in Buffalo NY and figured I did not need to worry about low underpasses. It was a truck route.  I was coming up on one and suddenly realized the low clearance 12'2' warning sign.  There was a car right on my A** and I ended up coasting right under that low clearance.  The roof of the box furniture trailer peeled right off just just like a sardine can.  After all these years, I still duck!

[bm02tj]

On 4/13/2021 at 2:15 PM, rayin said:

Right! At 55kmph a driver doesn't' have time to perform these mental calculations. That's one reason why all speedometers have both scales on the  readout. Feet to Meters is the same type conversion, only much less used in daily driving. I have a small permanent placard on the dash of our MH, it states " minimum height 13 feet/ 3.1 Meters. That worked great until the caravan leader happened upon an unmarked RR underpass in Newfoundland.  ( ´△｀)

13 ft is 4 meters   3.1 meters is closer to 10 ft     double check your conversion to be safe  

[rayin]

17 minutes ago, bm02tj said:

13 ft is 4 meters   3.1 meters is closer to 10 ft     double check your conversion to be safe  

Right, should be 3.9 meters. Anyway this thread is 32 months old and I've stopped visiting Canada and Mexico. There's only one highway in the U.S.A. with SI measurements

[aztec7fan]

Although our primary trip planning proceedures are using paper maps and google maps, i do also put our route into RV Trip Wizard which takes into account the height of our motprhome, which i physically verified by climbing on the roof and measuring in several areas.

 

There are also several RV specific GPS units that allow the user to imput their rig height and width and will detour the user around size hazards.

[donjlong]

We purchased a Rand McNally GPS designed for large rigs. It allows for the entry of all your vehicle measurements including weight. The theory is, it creates routes based around your rig and certainly for large vehicles; so far, so good!

[rayin]

3 hours ago, donjlong said:

We purchased a Rand McNally GPS designed for large rigs. It allows for the entry of all your vehicle measurements including weight. The theory is, it creates routes based around your rig and certainly for large vehicles; so far, so good!

IMO, return the Rand McNally RV GPS. RM says lifetime maps;  their website says they consider 3 years the lifetime of their products and will not support  your GPS after 3 years.

Rand McNally is now  out of the RV GPS business and instead are focused on commercial trucking and the boating industry.

Instead of spending a lot of money, I decided to buy a Chinese truckers GPS from Amazon for $79.(Rand McNally products are all mace in China too, you pay for the name) I've had it for 2 years now and it had been right every time I programmed in a trip. The OHREX map updates are $20 each and come on an SD card.

Edited October 9, 2023 by rayin

[five]

Garmin has a number of RV GPS models.  You put in the dimensions of your RV, including weight, and it will advise you if you are about to encounter a road or bridge that can not accommodate your RV's size or weight.