The original "Fare's fair" policy of Ken Livingstone (subsidising public transport and improving it so everyone would use it then there would be fewer cars on the road so the but part of public transport could get through speedily and safely) was one of his better ideas - but the Thatcherite legislation he had to work under enabled a successful court challenge to the obviously sensible policy.

Ho Hum.

I suggest really high fuel taxes, with a part of them being deductible from income taxes (or eligible for benefit if you are on benefits) if you can demonstrate that you need transport to work or obtain necessaries of subsistence.   

Businesses set them off against tax anyway - and non-business car benefits from employers are taxable for the employees, so the circle is squared. I think.