Typically 80,000 pounds is the max (gross weight) on state roads without a permit and then they will be restricted to roads and bridges that can handle them. (These are 18 wheelers) This is regional tho so YMMV. Out west they like longer configurations to spread that load out farther and decrease the spot load on bridges. In the east the use of double bottom trucks is limited if allowed at all. Length becomes a problem navigating winding roads and suburban streets. We had a car hauler in my neighborhood the other day that was on the grass on both sides of every turn.
That is why I said you might be surprised how much dirt you are talking about there.
150 yards is about 33000 gallons, a small public pool like you see in a motel. An "olympic" pool is considered to be ~650,000 gallons.