A tip should never be expected...it should be provided if you feel someone did an excellent job for you. Should you tip the ME driver? Here's how I come down on this one....
I have taken the DME many, many times. I have tipped and not tipped. I had one driver who was extraordinary. He was pleasant, greeted every single person that came to his bus. He told funny anecdotes about the area as he drove. He was a safe driver. I had no bags with me on that trip, but that driver got a $5 bill from me. It boggled my mind to see so many people taking their bags from him and just slinking away..and yes, some actually slinked.
But...there was the one driver I had who never greeted one single person as they boarded the bus. I had a largish carryon bag that was too large to go on the bus with me, so handed it over to the driver..who took it from me without even glancing up. We finally pulled away from the curb, after waiting close to 25 mins. That driver never said a single word, not one word, until we got to the first stop. At that point, he stopped the bus, told everyone to stay on the bus until he had unloaded the bags for that stop and that gratuities are always gratefully accepted! Are you kidding??? You never say a word except to tell everyone you want a tip??? And you hold all those people on the bus until you have their bags out so they have time to rummage around and get a tip ready for you?? He got nothing from me, not one dime.
So....do as you please. The driver is paid to drive you safely to your resort. But, if he/she gives you out of the ordinary service, or does something that you feel is above and beyond, by all means, hand over a tip. If a driver has to stow and then unstow a bag for you, a tip is recommended. Yes, I know...I had a bag and didn't tip. I will not tip someone who asks for a tip. There is signage at the front of each bus telling the passengers that tips are allowed.