I removed almost all public transportation, left the game for a while to let it recalculate and the sims adjust and force them to take their car.
Result, same, cars remain desperately parked and the streets are the same, empty
Taxis are more present and the sims have all become Olympic athletes and environmentalists, they all walk, the sidewalks are flooded with them with an increase in homeless people
so even there, already existing city 300k, and since the last patch, almost dead city, streets remains empty even without public transport