-
I don't think it's encouraging people to have two cars. The capital outlay for a car means that those that can't afford it aren't going to feel encouraged. However, if people are going to have two cars (a basic function of their buying power) then a stronger encouragement to make at least one of them electric should be considered. Bear in mind that the only problem that this is tackling is localised and nationalised pollution levels and nothing to do with either congestion or road safety.
Obviously I'm all in favour of people adopting the most sustainable transport options. However, without draconian regulation and enforcement, you have to accept that aren't going to achieve a transport utopia. Households will continue to own and drive multiple cars and there are a large number of social issues that are involved in that decision.
The Guardian had an article on that a few days ago. Still sounds a bit more painful than filling up with petrol. https://www.theguardian.com/technology/2016/may/27/tesla-model-s-electric-car-driving-holiday
The trouble is that encouraging people to have two cars, a city run-around and a big car isn't really tackling the problem.