We don't always travel as a family while on business trips, but when we do there is definitely things we have to do to ensure a smooth trip.
We have done several trips this past year, mostly within a 6 hour radius drive one way distance while with the entire family. My husband has also done several trips on his own (flying trips and much further distances.)
Some ways to prepare for a road trip with kids is lots of organization. You have to pack things to keep them busy, fed, and prepare for accidents (spills in the car or car sickness). You have to prepare for everything even if it doesn't happen. I'm sure you have heard the saying "better safe, than sorry." This statement can definitely be true with small children on a road trip.
Since it's also a business trip and we sell and show products, we also have to carefully pack it along with our regular packing and items as well. We try to keep all this separate and easily available from the other packing in case we have to take it out on the way for photos or showing.
I usually pack the day before the trip with a small checklist of what we will need. It usually contains a stroller for our little one with diapers and wipes, and clothes (also extra clothes) for him because babies can be messy. Next we pack a suitcase for the girls to share that include their clothes, bathroom items (toothbrush, toothpaste, hair things and hairbrush) and they each get to pack their own backpack full of activities, such as toys, tablets, and snacks for the trip. Then me and my husband each bring a bag/suitcase and he brings his camera gear and I bring the diaper bag that I leave by my feet for easy access on the road trip. We do try to pack fairly simple and we have not (knock on wood) forgotten anything major yet.
How we keep the kids busy and entertained can be a little bit harder task with a one year old, but sisters are very big helpers and we make plenty of stops on the way to our destination. It can make for a little big longer trip, but it's definitely worth letting the kids out and stretch. Several of our stops we also try to do a scenic look out or historic place that kids would enjoy instead of just a rest stop. It seems to help them with the monotony of travel.
Another thing to think about on a road trip is food. We always try to buy snacks before we go, because gas stations are not always the most thrifty on prices. It's always good to save money when you can with an almost family of six. We usually head to the local grocery store or Costco the day before our trip. Also we try to get a hotel with free breakfast so at least one meal a day is taken care of. Another helpful thing so you don't eat out constantly which is not always the most nutritious, is also do a small grocery shop when you get to your hotel since a lot of the time they also have a microwave and refrigerator in your room. Also you can call ahead to your hotel if you aren't sure, which is a good idea anyway to confirm your reservation.
Another helpful thing we do is to make an itinerary (at least a tentative one) especially if you are going to certain events (such as a trade show) and you need to know when you need to be there, so you can plan ahead. Also you could end up somewhere with hungry kids and no place to get food at the time without a schedule. Always pack some snacks just in case though.
Well, I hope this has helped you try to stay organized with kids while on a trip or business trip. Try to remember to be patient, because it can be out off the kids comfort zone sometimes and can be difficult, but if you have some plans in place, it can definitely help keep them happy!