I have the same trouble sleeping the night before a road trip.
I believe it's because I am so excited about leaving on the road trip in the morning and can't wait until the next day arrives so that I can head out on the road trip.
Still I and everyone else needs sleep and to be well rested before setting out and driving on a long road trip to have a safe trip.
You might need to try taking some sleeping pills or drink some relaxing bed time tea the night before heading out on the road trip.
Make sure you have everything packed the night before so you do not have to pack anything in the car the next morning.
Then all you have to do is get in the car and head out on the road trip.