After leaving NY, Jane and Robin appear to drive an entire day & then spend the night in a motel. There, Robin mentions to Jane that in order to get to Pittsburgh by noon the following day, they'll need to leave by 8:00am. Pittsburgh is less than 6 hours from NY which means they would have only driven 2 hours on the 1st day before stopping to stay overnight in a hotel.
Just before the diner scene with Holly and Robin, there is an outside shot of the van driving and Holly is clearly seen in the back seat. In the very next shot, from inside the van, Holly is driving.
When the doctor is talking to Jane after Robin is rushed to the hospital, she says that Robin is "going to the eighth floor". But exterior shots of the same hospital throughout the film show that it is only about four stories high.