I travel 12 miles, it takes 45 - 55 minutes by bike, and 30-45 minutes by car (depending on traffic), in part because I haven't shelled out $300 for a parking pass, so I have to poach a parking spot in a shopping center and walk in 10 minutes. A parking pass would cut 6 or 7 minutes off that time.
I could drive, but I've never been on the bike and thought, "Gee, I wish I'd taken the car today". I have, plenty of times, been in the car wishing I was on the bike.
There is also a bus option, though to be competitive, it's a bus/bike hybrid. Straight buses are over 1.5 hours travel time, plus timing arrival slots. With the bus-bike, it's about 55 minutes, or the same as bike alone. I do have a free bus pass, so the cost is identical, the only significant difference being timing the pickup and more roads/cars on the route.