Allow a little playtime while you stop for your own break.Transition timing of routines slowly a few weeks before you leave to accommodate any time-zone changes.
Pack water from your own tap bottled in milk jugs or smaller bottles to keep your cat's stomach from getting upset due to drinking unfamiliar water.
Feed and provide water for your cat along the way at times it would normally eat.
Set the carrier out in your house a few days before you travel so your cat can get used to it. Take a few short car rides with your cat in the days before you leave if traveling by car.
Search towns along your route for emergency vet locations.
Crack windows about an inch if you get out of the car for any length of time, but don't let the cat roam the vehicle.