Based on your comment, I have to assume we live in different areas. I live in the city, and generally it is better and faster to bike because one can bike almost as fast as a car due to not needing to wait for traffic and there's no need to find parking at the destination. From my POV, the motorists I have to share the road with are driving on low throughput streets and generally don't belong on the streets I am traveling down.
Do you live out in the country with 2 lane roads? A small town?