You might, but it would make me nervous. We had an 11:30 flight (non-stop) from Raleigh a couple of years ago (pre-9/11) and we made it (we used Disney transport to the terminal) but I'll tell you, I had stomach cramps the whole time, I was so nervous. The bus driver told us that we were about the last people coming to the boat. Everything had to go exactly right. If we had encountered a delay anywhere, I don't think we would have made it. We got to the check in desk about 3:00 and on the boat by 3:30. With today's security measures and everything taking longer at both the airports and the terminal, I'm not sure I'd chance it plus, if you're in PA, you have a little more distance to cover than we did from Raleigh. And I don't know anything about Happy Limo and their reliability. It's up to you, but I know I'll never cut it that close again.