I know and I have read that too, but I'd love for someone to conduct a study. In order for driving to be faster, the amount of time to get through the booth to pay for parking, park your car, and make it to the gate would have to be less than the average amount of time people wait for the bus. There have been a few times where we have waited a ridiculous amount of time, but there have also been countless times where a bus pulled up within less than 5 minutes. In those cases, I believe it would be faster to take the bus than to drive (because it would take more than 5 minutes to make it from the parking lot entrance to the gate.)
It's certainly possible that my parents are just slow, but I would think they would at least try to beat us
once to prove that they're right about driving being faster.
We have also beat my brother driving several times but he has young kids so it probably takes him longer to get them into their carseats.
The only time we have "raced" with us driving was on our last trip, but that was MK so can't accurately compare to the other parks. DH and I were pretty determined-- we left the park before the rest of the family (they were leisurely getting a snack and using the restroom) and we literally ran to the car (which was parked closer in the handicapped lot so no trams), but they still beat us and were already taking showers and relaxing by the time we got back to the room.