Can anyone recommend ways to eat healthy on a road trip?

I just took a road trip down to FL to visit a family member that was ill. The trip was last minute, so I didn't have time to plan. I had to eat fast food on the way there and back. I have another trip coming and I don't want to eat the same way. I don't have a lot of room for a big cooler. I have a little one. I was thinking like some nuts for snacks. Any first hand experiences of eating health on the road will be greatly appreciated.