Tunnel Heights

[SuiteSuccess]

Are the height signs for arched tunnels to the lowest point on the wall or to the center of the arch?

[Big5er]

Carl, they "should" indicate the height so that a vehicle traveling through the tunnel, IN it's own lane and lower than the height posted will fit. 

 

[Yarome]

Depends on the state and signage. Typically, and if the sign lists nothing or just "height" or "clearance", it's the minimum clearance measured from the edge of the roadway or the lowest overhead obstruction.... although it's sometimes measured at the edge of the shoulder. If the sign specificilly says "max" height/clearance it's measured at the center of the roadway and "min" height/clearance" is measured at the edge of the roadway.

[adept99]

5'er,

Where Carl & I are located, the tunnels here are old and small even for mining carts. So...sometimes they're marked at the center of the arch, sometimes at the top of the vertical wall, sometimes splitting the difference, maybe not marked at all. Watch the traffic, slow down, and beware of New Pavement

[SuiteSuccess]

Thanks guys.  Was considering looking at some roads in “our neck of the woods” as Paul says and when using Truck & Travel App it just says height 14’3” which is fine if it did not mean I had to be over the center line.

[jkoenig24]

Carl, there is a LowClearances app that you can buy. Once you've downloaded their database, it can be installed on your GPS device.

 

http://www.lowclearances.com/

[SuiteSuccess]

Thanks John.  My Rand McNally can be programmed for low clearances, but bet your app is more inclusive.  

[lockmup68]

also, on older roads/bridges especially, if it is really close, hope they have not overlayed pavement since they measured. You might have seen the big CAT dump truck on trailer that took out bridge in Nashville a few weeks ago. They supposedly had 6 inches of clearance, but since they repaved 8 times since the last measurement, they were 6 inches over. Or it was the driver's fault. There was no clear determination last I saw. 

There is a bridge by Montgomery Bell State Park that says 14' on it. But I am willing to bet, there is no more than 12' clearance under there. I stopped and turned around. A travel trailer in front of me looked like it barely cleared and I am at least 3-4 feet taller than that.