jyajaz wrote:bobcat321 is right though.
Maybe the person was late to post it but this can not be say on a way to somewhere. It does not mean "I'm on the way", literal translation is "the wheels are ready to roll", real meaning is "We are ready to go".
I didn't say that Bobcat was wrong. Although I don't see it your way.
พร้อมล้อหมุน I read as "เตรียมครบถ้วน ล้อหมุน" there is no future tense in ล้อหมุน is there? It was sent by the passenger sitting in the car, I know that because he would hardly be standing outside as the last passenger's gear is loaded delaying proceedings while he posted on Facebook informing all his friends that all was prepared and that soon the wheels would be going around. That sort of thing is done after the passenger is satisfied that the car has safely joined the traffic flow and is now settled en-route.
That is how I understood it, and I do think that I understand it because I can picture the scene having been part of similar scenes so many times.