Considering the ever-rising price of fuel, the ridiculous cost of parking and the clogged state of our roads, I'm surprised we haven't seen an increase in smaller forms of transport. How often do you drive your car with more than just you in it?
So why haven't we seen a rise in motorcycle ownership (technically we have, of more economic models, but I don't know of anyone who has bought one)? One answer is that motorbikes aren't much cheaper to run than a car (most bikes won't beat a diesel on MPG, require more frequent servicing and require buying safety equipment), plus they have drawbacks such as requiring another licence, they're not great in inclement weather, you can't just get in and go like a car, there's safety issues too (they account for 1% of traffic but make up 20% of deaths and serious injuries).
There's the scooter option, no licence required, just pass a CBT and you're away, but you still face many of the same issues as motorbikes (they may be cheaper than a car to buy but they don't get good MPG).
Several attempts have been made to crack personal transport, we can all remember some of those that failed: the Sinclair C5, the Segway, etc.
So what is it we're looking for?
Even if you tick boxes like stability, safety, ease of use (get in/on and go) and cost savings, both upfront and ongoing, you have the issue of storage (no everyone has space for two vehicles) and flexibility (a car simply offers far more).
Maybe that will change, with options like the C-1, which is a 'self-balancing electric motorcycle.' It's covered and can withstand the impact of an SUV (apparently). It won't be cheap though. The Renault Twizy was another option, but its short range and open cockpit mean it's far from ideal, even in the city.
There always seems to be a new small car/vehicle option but, with the exception of Smart cars (which don't really count as you can buy a regular supermini cheaper) none seems to have found a mass market, I suspect because of cost and flexibility.
So even if you invent something with four wheels (for stability), fully covered (for safety and to keep out the elements), boasting great economy (without sacrificing too much range), with at least some storage space and offered it at an affordable price, I doubt it'd find a big market.
What we need are more flexible cars, perhaps using some sort of pod approach where you can split and combine individual units (I'm going to call them carites) to make smaller or bigger vehicles. It sounds good but is likely implausible. Instead we're forced to try and buy a car that will cover all our needs, and some we may never actually encounter.
If we're never going to embrace small vehicles, what are the other options?
I'm not sure that being able to more conveniently rent cars is the answer, though offering reduced rental periods could pay dividends for car rental firms I think (and van rental firms especially, hourly rates would be a good idea). Not owning a car in a major city may be an option, but it's becoming less so outside one.
Perhaps manufacturers of small cars could hook up with rental firms to offer a package where you can easily and cheaply swap your car for a model that better suits the task as and when you need it. I could happily drive a little supermini most days but I wouldn't want one on a 300 mile round trip, or if I need to transport a lot of equipment. If a buyer could opt for a small, cheaper car yet be safe in the knowledge they still have the flexibility of an all-rounder then more people might be prepared to gamble. It does require people to plan some way ahead though, something that's not always possible in our hectic lives.
More and more I think self-driving cars will provide the answer (and not just to car use), offering you the ability to request a car to fit the job at hand (a small car for short journeys and a bigger one if you've got a lot of passengers or want to cruise the motorways). Not owning a car at all doesn't really work if you have to get to the rental place and there's no way to offer the density of locations to ensure there was always one nearby outside a city, so you'd need the car to come find you. It still requires advanced planning though. For regular journeys we could at least schedule it in (going to work each day, for example).
I doubt anything much will change soon, small cars will continue to be reserved for second or backup vehicles, but if we can perfect reliable self-driving cars I think we'll see a revolution.