L.C.
Dear P. B.,
We travelled often with our two daughters when they were that young (10 months) and younger. We stopped frequently (like at least every 1 1/2 hours) and let them run or crawl (when that was their mode of personal conveyance)and showed them whatever we were around that stop. If there were flowers we would point out all the colors and name them or if there were dogs we would say what breeds they were, etc. It gets their minds off of how tired they are of riding in the vehicle.
Be sure to take a couple of his favorite toys to play with while riding in the vehicle and especially his favorite sleeping toy for bed time. Plenty of water during the trip is a good idea because travelling can make some constipated and you don't want that in a baby. Apple juice for adults can be diluted 2/3 juice and 1/3 water will help if this happens.
Be sure to have a soothing routine before bedtime for the night so he can relax and calm down, especially if he has had a lot of stimulation during the day.
L. C.