If buses and cars participate in the same road traffic (i.e. the bus doesn't have dedicated lanes), then a bus trip will never be faster than a comparable car trip. This is because you have to walk to/from the bus stop at both ends of the journey, wait for a bus to show up, ride the bus and have it stop for other passengers, transfer between routes, the bus has slower acceleration and turning than a car, etc.
Think about even the most strawman trip possible: A bus rider and a car driver start exactly at the location of a bus stop, the bus shows up exactly at the start time, both contestants ride/drive straight for a few kilometres (which happens to follow exactly one bus route, without changing buses; but the bus might stop a few times along the way for other passengers), and end exactly at a bus stop. The car will win every single time.
Think about even the most strawman trip possible: A bus rider and a car driver start exactly at the location of a bus stop, the bus shows up exactly at the start time, both contestants ride/drive straight for a few kilometres (which happens to follow exactly one bus route, without changing buses; but the bus might stop a few times along the way for other passengers), and end exactly at a bus stop. The car will win every single time.
https://en.wikipedia.org/wiki/Downs%E2%80%93Thomson_paradox , https://www.youtube.com/watch?v=RQY6WGOoYis