I delivery materials with a tri-axle dump for other contractors. Waiting an hour is not that big of a deal. If the truck is busy like it should be than lots of factors come up in the day that will put the truck behind. We do try and call with an ETA. Hard to find loyal vendors also.
Before I owned my own trucks I waited all the time, didn't matter who I bought from. Try waiting for a concrete truck, late every time.