What happens when the width of the driveway - for how many cars it is designed to hold across it, from one to four or even more - is filled with that number of cars? For instance, a single car driveway has a car parked in it - possibly even more than one car parked behind the one in front of it. Where does someone stand if they need more space to get in or out of the vehicle?
Two car driveways often have two car (or trucks or vans) parked side-by-side next to each other, and frequently more than two cars are parked there. Unless the community regulations require that vehicles be parked in the garage overnight, many cars remain parked in the driveway without being moved into the garage.
Typically grass, flower beds, or even dirt (which turns to mud after a rain) are adjacent to a driveway. When the driveway is full of cars, there is little-to-no room for people to stand when they get in or out of vehicles on the driveway. If it is a two-car or wider driveway and there is just a single vehicle parked on it, there is room to get in or out or a parked vehicle and stand on the hard-surface driveway while doing so rather than the ground.
When someone uses a wheelchair and needs to get into a vehicle, having a hard-surface base such as the driveway is safer and more convenient than attempting it from the grass or soft ground. Loading or unloading pets, children, groceries, items picked up through various shopping errands, or school projects and supplies is much easier when done from a hard-surface.
So to insure that a hard-surface is always available to use - even when the number of cars for which a driveway is designed is already parked on it - design the driveway with an extra strip on paved area. This can be concrete, asphalt, or brick pavers. It can run the entire length of the driveway to add as much as an entire extra driving lane, or it can be just the size of a car or so in length and width.
During all of the times when that extra space is not needing fro vehicle loading or unloading, it can have lawn chairs placed on it for sitting, have a motorcycle, bicycle, or golf cart parked on it, be used for playing basketball (when a hoop is set up in conjunction with it), have a barbeque grill placed on it, or other similar auxiliary uses.
This is an effective and safe solution for providing additional comfort, convenience, and accessibility for people living in the home as well as anyone who might be visiting - a great universal design feature to recommend and include in new construction or home modifications.