Gear Jammer: I am more than certain that you have many more years of experience than myself driving HGV's, and normally I would respect your opinion on all matters HGV.
However in this instance I cannot respect your opinion.
The way I see it (and some may disagree), when I get into my truck which has the companies name on the cab door in six inch high letters, as a professional driver and, a representative of my company, I have to uphold certain standards of driving.
I feel that passing under a bridge marked 14'3" in a 14'6" truck is below the standards that the driving public expect from people who earn their living driving these vehicles.
I consider that I am capable of judging weather my vehicle will fit somewhere fairly well, however if a road sign says that my vehicle is too tall I'm not going to argue with it, regardless of how pessimistic the sign may be.
The way I see it I am driving tens of thousands of pounds of someone else's property (Including Unit, Trailer and, Load), it's not mine to take risks with.
I would rather take a detour around the houses and arrive with the truck in two pieces, than take a risk and turn a curtain sider into a hopper, and probably lose my licence in the process.
On the subject of sat-nav's they can be a pain in the backside. I prefer to use mine in addition to a proper map rather than instead of, plus I have a road atlas that shows the heights of low bridges so I simply plan my route around them.
Granted i have only been less than 2 years behind the wheel of a truck, and I have had an accident (although this was found to be the fault of the other vehicle) but I have not yet hit a bridge and I fully plan to keep it that way, by avoiding low bridges like the plague.