Making good provision to allow people to walk, cycle and use public transport is a sensible thing to do even if you don’t give a stuff about the negative environmental or social consequences of driving a car and want to drive everywhere. Forget the green stuff*, simple old fashioned self interest shows it makes sense.
I’ll use the Isle of Wight as an example. We have a limited road network, little chance of major expansions to it and a population which mostly lives in small towns and large villages. For a rural area we have fairly low car ownership, and a higher than typical number of car-free households.
If our car ownership was more typical for our population density we would expect to see an extra 6,000 cars on the road (and this number could be much higher). Let’s ignore the impact that would have on congestion and demand for workplace parking and look at one single issue – overnight parking. A large number of these “new” cars would be owned by currently car-free households, some would be second/third etc. cars within a household. Given the makeup of Isle of Wight housing I think it is fair to say the majority of these cars would be parked on-road overnight. Conservatively let’s say 65%. Allowing 5.3 metres of space for parking (and people are going to have to get better at it if that’s all we use…) that’s 20.7km of extra on-road parking that needs to be found. I don’t know about you, but I struggle to see where we will find the space to put those extra cars
So, if we want to avoid this, doesn’t it make sense to ensure people have some good quality alternative options, so they don’t have to buy a car (or a second car, or a third car)? Wouldn’t it be better to invest in cycleways, making junctions safer for pedestrians, reducing traffic on side roads and improving public transport infrastructure and service provision than building 20km of new roads just to park our cars on?
(* Actually I’d rather you didn’t, but if you must…)