I've been looking into a quick and efficient way to gather data on overhead clearances on our highway system. The trick is I need to get the clearance of each lane that goes under the overhead object (which includes; bridges, railroad crossings, signs, signals and anything that hangs over the highway) and don't want to play frogger in the middle of the street . I have my hands on a laser range finder and have found a few apps that can calculate height/distance but not sure how accurate I can get from being on the side of the road.
Thought I would throw this question out to get more ideas on any way to get heights that could be more efficient (and/or more fun) than trying to point and shoot from the side of the road to get height measurements?
Every state must maintain and inventory of all Bridge Structures (This includes overhead signs and high masted lights). Part of this inventory is the vertical underclearance (Min/Max values). So checking with your states NBIS Inventory you may be able to obtain the clearance for the majority of your structure leaving you with a few that you would have to obtain manually.
Hope this helps!