[jandrese]

Also, there's an assumption that the car is going from someplace in the city to some other place in the city.

It almost certainly will not be faster to bike from a suburb 20 miles out of the city into the city than it would be to drive.

[Skunkleton]

That isn't always true. I commute from a downtown to an office park in a suburb (against traffic when driving). On my bike, it takes about 40 mins (~11-12 miles). The same commute in reverse by car is about 45 mins due to traffic. If I instead lived in the suburb and worked downtown, it would be a tossup travel time wise between my bike and car.