Just a suggestion, MAKE it back. DME is based on reservation ONLY as others have said. If you miss YOUR bus, you are NOT guaranteed a seat on the next bus IF there is one. You are asked to be there 15 min prior to departure, and I might add that includes having ALL your belongings, family, and luggage there as well. I left 2 people today, WHY, they didn't show up until 5 min after my stated departure time ( I was just finishing loading luggage and signing "the book", and still they didn't have their luggage together.Then I waited 2 more minutes, Then, I said NO, you can try and get on the next bus or take a cab, "your gamble" but I have to go, I have 40 people on board that were ONTIME that want to get to the airport ontime. And I left. END of story. If you wish to use the DME system, then follow the guidelines and all will work as intended. A system transporting 14,000 to 27,000 people a day MUST have guidelines that MUST be followed by the DRIVERS AND THE GUESTS. It may not be for everybody, that's for you to decide.