Potty training doesn't have to stop when you have to travel. Preparation is key when continuing potty training on the road.
First off, bring your child's stand alone potty chair with you. If it comes down to it, you can always pull off the road and set the child's potty chair up in the passenger side seat. Be sure to bring inserts or small plastic bags for lining the potty. It will make clean up a lot easier.
If you bring the potty, be sure to remember paper or wipes for your child. Bring whatever it is she uses at home. A long trip is not the place to experiment.
Have your child wear one of the many disposable training pants that are on the market. This will protect clothes, car seat and tender little feelings from the occasional accident.
Try to limit fluids and high water content foods on the road. Hydration is a good thing, but you don't want your toddler to have an accident because you can't find a place on the two-lane road to pull over.
And don't forget to stop often so your little one can use the rest areas bathrooms. Just bring the child's potty seat in to the restroom with you. They may be afraid of the toilet, so don't be surprised if your little on insists on using the full potty chair.
Also, it is normal for there to be potty training backslides during periods of high stress or travel. So, don't be to hard on your little one if they suddenly start having more accidents than at home.
When you arrive at your destination, try to encourage you toddler to get back on their normal potty routine as quickly as possible. You will both feel better when you get home and back to your routine!