We wouldn’t ever expect public transportation to be significantly faster than driving the same trip. If it were, people would switch from driving to the faster option. Decreasing the number of cars would then ease congestion and speed up driving, until a new, faster, equilibrium was reached.[0]

This is how improving public transportation is actually one of the most effective ways to benefit drivers.

[0] https://en.wikipedia.org/wiki/Downs%E2%80%93Thomson_paradox