The answer lies in the substantial savings from not having to own a second, or possibly any, car, according to planner Patrick Hare. See Tables 1 and 2.
Local buses are still slower.
Buses and trains are also worse than cars for comfort, security, privacy, weather, transporting parcels, and a number of other functions. The answer won't be found in transit's speed or convenience. See Table 3. For many, households, that will mean a 10 percent increase in disposable income. That is a genuine reason for many people to use transit and occasional car rental.