- A train will take you right into the city center, sometimes even where cars are not allowed. OTOH entering the city from suburbia can take an hour of being stuck in traffic.
- metro and trams can skip traffic. Bus lanes are common. There are no "stroads". Average car speed in London is 12mph. That's slower than a bike.
- Finding a parking place can easily take longer than waiting for public transport, and it will probably be an underground garage, far away from your destination. Bus stops are much denser than parking garages, so they usually involve less walking.
The US experience of driving on an 8-lane highway and arriving at a mandatory-parking-quota asphalt desert in front of your destination is rare in Europe. The closest we get is a 3-lane motorway to an IKEA on the city outskirts.