Truck Pathing/Dumping Improvement

Trucks repeatedly try to path to targets that are not reachable when there are other, reachable targets that accept the same dump materials. As a result, they get stuck.
Suggetion to change the pathing so that if it fails to find a path to a target, it resets (and ingores that target) and attempts to find another target. Only report the "no path" alert if it fails N times.
Also, dump zones should be able to accept from multiple trucks at the same time depending on the terrain height and the difference to the dump height for a given grid column. This should be able to be calculated to an "amount of material" required to fill that volume. If the result is greater than that of a single truck, then allow multiple to dump at the same time.

I have a guess as to why this is, but not how to fix it, I believe this happens because each square marked for mining or filling is 1 job, each job can only have 1 vehicle assigned to at any given moment, because said vehicle could finish the task once it's done. So if you are trying to build a 5 wide bridge, only 5 vehicles will attempt to fill it, one for each available square, so when all 5 of them are assigned other vehicles look for other jobs, like the 5 on the other side of the bridge your building that are still connected to land so are technically available.
From a player perspective the solution to this is just to add extra places to dump, from a developer then maybe allow the jobs one beyond the current line of fill/mine to be assigned, and when they arrive if they can't reach then try to dump in the nearer squares.