Billing for idle travel time, but not double-billing travel+work makes sense. The premise is that travel is wasted time by the lawyer - that he could have used

Billing for idle travel time, but not double-billing travel+work makes sense. The premise is that travel is wasted time by the lawyer - that he could have used for another client or family if he did not have to travel. If they can bill another client during travel, then it wasn't wasted time for them after all.