As much as this seems fairly straight forward, it’s not always possible.  On many lease, construction and commercial sites involving large equipment, many times we see the identifying line to show “danger, overhead power lines” marked well in advance (usually when equipment crosses underneath it’s at a minimum of 3m away), for clearance purposes. When I train with companies, I always ask, what is the travel height of the vehicle you are driving (doesn’t have to be the crane truck), and most drivers have no idea.  Why not take the time to put it on the dash? Sadly, in this photo to the left, the operator did not survive, and yes I get that people say “He/She should have never