I've been thinking about this (increasing) need as well. I'm not certain how this idea could be incorporated on a community scale. I live in Amish country and there are roads that have lanes specific for buggies (which saves a lot of lives). Perhaps a version of this could be modified for the elderly. I could see drivers licenses having this as a restriction for some elderly people. I also think the idea of geriatric mobility may need to be specific to locations (ie. people movers incorporated into malls, stores, etc.) I believe that this is an issue that will HAVE to be dealt with in some fashion.

In Europe following WW2, a number of "invalid cars" were devised, generally powered by 2-stroke engines of less than 200cc displacement. Often they were equipped with hand controls or other devices to compensate for operators with missing limbs. Some of the better-known examples were the Czech-built Velorex Oskar, the German Fend Flitzer and Messerschmitt Kabinroller, the East German Simson Duo, and the English Invacar. Photos of restored examples of these may be found in the Internet at such sites as the Microcar Museum and 3-wheelers.com. The Velorex and the Simson were derived from production motorcycles.

Lately this need has been met, at least in the US, by the combination of the powered wheelchair and the wheelchair-lift-equipped minivan. Unfortunately, not all handicapped individuals are able to afford such equipment.

This issue touches on another subject of interest to me, the single or two-seat "all weather motor scooter" or "cabin scooter" commuter vehicle. An American example from the 1980s is the HMV Freeway, about 700 of which were built in Minnesota between 1979 and 1982. I think a vehicle could be designed and built that meets both needs, priced affordably at under US$8,000, and I'm currently exploring that possibility.