Is there any way to access your ATC provided routing before contacting Ground/Clearance Delivery? On a recent flight, I was told that there would be a lengthy delay in getting my clearance due to the routing, then I was given a route that took me into weather requiring deviations that my filed route would have avoided. (Yes, I did look for recent or ATC-assigned routes in 800wxbrief, and my filed route took me away from the Bravo airspace)

Perhaps I am missing something, but I don't see anything on the Lockheed Martin 800wxbrief site that allows you to see your assigned routing. Should I call the tower on the phone to get my clearance before I start the engine (or would they consider that a nuisance)? Should I call 800wxbrief to asked about the assigned routing? It just seems with the technology at our disposal, there should be an easy way of finding the ATC assigned route in advance, and, even better, to try to negotiate a route before starting the engines.