Before embarking on a road trip with a car full of kids, make sure everything about the vehicle is in top working condition, including the windshield wipers, A/C, heat, fluid levels, seatbelts and lights (exterior and interior).
Hopefully you'll have a GPS; make sure that works, too; they've been known to malfunction. Have a backup mobile GPS app too.
While on the road you may hear a lot of "Are we there yet"s. Feel free to announce, "Next one who asks are we there yet will have to do 20 pushups." Just kidding, but seriously, come up some way to discourage any nagging if it bugs you enough. Kids iPads loaded with family moves and a good headset are the best tool ever invented for parents. My Aunt used to have a yard stick on the dash. Us kids still have scars from it. I wish we had iPads!
- If you'll be driving in a foreign country, make sure you have everything you need in the car that the country requires.
- Have emergency supplies: first aid kit, nutrition bars, flares, flashlight, pepper spray (check laws), blankets, water, motion sickness tablets, etc.
- Don't load the kids empty-handed; give them coloring books, crossword puzzles and other age-appropriate word games, 3D puzzles that will keep them occupied for extended periods trying to figure them out, etc.
- Give older kids (8-10) a long word that you can make a ton of words out of, such as "Transportation." Arm them with a pencil and paper on a clipboard and give them a command to "Go" once you're on the road. Who will have formed the most words by the time you get to your first rest stop? Every word formed gets them a dime. This will pretty much guarantee stillness and quiet among the participants.
- Do not tolerate resistance to seatbelts. "The car won't start till everyone's buckled up."
- Pack snacks such as raisins, bananas, apples and nuts.
- Take a rest stop at least every hour to 90 minutes. Not only do the kids need to get out and move, but remaining cramped in a car for extended periods can lead to a blood clot in the adults' legs!
- Sing-alongs? I don't know. Not my thing.
- Avoid loud music; the driver needs to hear sirens and honking horns. Unless it's Led Zeppelin.
- Forbid screaming, yelling and hitting. Such can cause you to lose control of the car or miss an exit. Issue all the rules before you even get the vehicle out of the driveway.
- And last but not least, everyone must relieve themselves prior to traveling whether they feel a need or not...before getting into the car.