[SML] Read the sign

[Joe D]

The hight of the bridge clearance may change slighting with temperature as the structural members change their lengths. But, a vehicle height will change a lot from a variety of factors, including temperature, barometric pressure, and mostly the load.  the load includes fuel, passenger, and of course, the load in the cargo area.  I would suspect that bridge sign-makers included a fairly generous clearance.

One theater I am aware of, estimates their rigging height to vary around 6" over the years due to temperature variations and snow load.

-Joe