I'd love to rely on free/public transport, however:
To get to my work from my home, would take two hours by public transport (walk, train, bus, bus, walk), however takes 20 minutes by car, or 15 minutes by motorbike.
I'm priced out of homes in the area where I work, so the only place we can afford is 10 miles away.
Cycling could be an option, but as my work won't provide a shower, and one of the hundreds of huge pot-holes on my way to work could kill me, an unlikely one.
If Labour opened up some of the old stations that they promised, improved the reliability and frequency of rural and semi-rural bus services (i.e. opened the routes up to decent competition, rather than the big three companies), filled some of the bleeding pot-holes, and reduced the price of public transport, then maybe it would work.
As a comparison, if Labour re-opened one of the old Leeds stations that they promised to in 1997, then it would only take me half an hour to get to work by public transport.
One thing I would say though, is seriously consider getting a motorbike or scooter instead of a second car. It's much more economical for commuting, and quite a lot more fun! The drawbacks are the weather (well you've still got your car) and the fact that you're less well protected from other road users and the road, however, it does make you a much better driver!