But public transport in some areas has been shit for decades (including under Labour Governments), even if the buses are frequent the routes are just insufficient if you expect people not to use cars.
If I wanted to get to my workplace which is in the next town, I can either drive 20 minutes or I can walk/drive 2 miles to the train station, get a train into London, get the tube a couple of stops, get the train back out of London, get a bus from the train station, walk 15 minutes from the bus stop. Not only would that cost the best part of £50, it would also take about 3 hours each way which is just not realistic.
I can't cycle because part of the journey is on the motorway and to go round would take about 90 minutes (we have no shower facilities at work, and hotdesk so have to carry all of our equipment)
Having a car is not a choice, it is a necessity if you actually want to have a job. So anti car policies have a big impact - it wasn't the 'rich or stupid' (as per pp) that object to the ULEZ expansion because they already had cars that were ULEZ compliant, it was the minimum wage workers already on the bones of their arse who have no other options and need their car to be able to make a living