I've seen some "creative" stuff over the years and I saw something new yesterday. An electrical contractor is working at a neighbors' house installing extra circuits for yard lighting. To get the circuits fro the new sub-panel to the yard they have to cross the drive way. Instead of the usual, under, over or around scenarios, he has removed the expansion joint material and a deco drain from between the garage slab and the driveway and is running rigid conduit in the gap. From what I've been able to gather, the plan is to then cover the rigid with sand and top with an elastomeric joint filler to refill the joint. Now besides the fact that the deco drain was probably put there for a good reason, is there also an issue with possible crushing of the conduit from the expansion during the hot AZ summers or can rigid take that kind of pressure? I don't think there is much of a pressure issue from the car tires as the gap is only wide enough to allow the conduit with a little extra room, and vehicle tires would span the gap. Doesn't code say so many inches under driveways and walkways?