It has been many years since I have done much traveling of any distance with w/c bound folks. Back in the 1980s I was a recreation therapist and we would take a group to Florida from the Midwest for spring break and I have worked one on one with people in their own vans for short trips. I have been an occupational therapist since 1995 and worked with many w/c bound folks. There are many different variables. Like are you traveling with someone in a manual or electric w/c? What are the physical capabilities of the person, like can they transfer themselves to and from the chair or do they need help or equipment, and also what are the person's toileting needs. Do they have catheters, colostomies, use a brief or able to manage their own care. (I know that usually freaks people out, but it is very real for people depending on the injury or illness. Not trying to be gross but it is a part of the human condition).
I would think in very general terms it may take a bit more planning as far as bathroom breaks. Especially with the covid thing going on. I know the facilities in rest areas and such were closed, etc. Being aware of accessibilities when you stop, as you can't always push or drive a wheelchair in sand, mud, grassy areas, etc. Are there curb cuts, stairs, etc. We are suppose to have an accessible society, but in reality it is not always true. The last thing to think about is the person going to sit in the w/c in the van which you will need to make sure you have good tie downs and a seat belt to hold the chair in place or will they transfer to a seat then need a place to store the chair. An added storage platform to the bumper hitch is helpful for this. I'd be happy to help you problem solve your specifics if needed or check in with some of your local resources. Of course Google and you tube... Lol.
Many variables to think about... I've worked with guys who have fallen off ladders and broke both legs and arms needing more help for a temporary time period to those with MS or CP whose conditions require more assistance and maybe a place to lay down to rest or stretch out due to spasms and also with guys who are paraplegic but are very independent.
So really use of common sense is the key, watch for extreme temp changes as heat and sun exposure affects people differently (some medications greatly limit people's tolerance to extremes), need for rest breaks, making sure food is available especially with diabetes and when taking meds. Also making sure they have and/or will be able to get their needed medications while on the road. I also kind of keep an idea of where care centers or hospitals are along the way in case medical assistance is needed.
I know this was probably more than you wanted to hear, but just some basic information. Good luck and safe travels .
Gibby