Mass transit is a viable solution to people only when it's more convenient than cars. When the hassle of driving and finding parking is less than the extra walk/transfers/etc of taking transit, most people will drive. If you have mobility issues or have cargo you need to haul back, you're even more likely to drive.

Here in Seattle our roads are at capacity and the city is actively working to increase density, creating a virtuous circle of improved transit availability and frequency. This is great when I need to get to the airport during rush hour - I live near the UW and can take the light rail and be guaranteed to be at there in an hour, with a bus transfer. Outside of rush hour, I ask someone to drive me there in ~25 minutes. If I lived farther away from the nearest light rail station, I'd necessarily choose to get a ride every time.

Unless your city is actively making transit a priority, or its road system is packed to the gills, the shift from cars to transit is not going to happen on its own.

article on falling US transit ridership: https://www.washingtonpost.com/local/trafficandcommuting/fal...