The only of my bike commutes I ever did by car was to/from the university (11 miles one way): I took a taxi a few times for whatever reasons. When there is little traffic, a car is fast (obviously), especially since you can take expressways for about half of the way. However, there are often very long traffic jams in the afternoon (and sometimes in the morning) and the car can get stuck there for good. Happened to me....

So that commute was something like:

car: 25 mins to 1 hour+
transit (subway + bus): 45 mins to 1 hour+ (depends on lines at bus stop and various delays)
bike: consistently 50 to 55 mins. Add extra 15 mins for a flat (rare).

So while bike was not always the fastest, it was by far the most reliable.