Bikes are faster than walking and you can attach a trailer. I know a lot of people do that in denmark. Suddenly your cargo capacity is larger than a lot of cars, of course not for weight. As for people with mobility issues, where i live they have a dedicated branch of the public transit for them. On train you can go with wheelchair and if you need extra help in the city they can send you someone with minibuss to help you. Same if youre not in a wheelchair but limited because of your age. Of course these arent cheap to solve but putting out the la fires that were caused by global warming that was in part caused by cars isnt cheap either.