Actually, for anyone living in an actual city, bikes and cars are generally roughly equivalent in terms of trip time. For example, I have an 8km commute on the outskirts of Paris - it takes about 45mins, regardless of whether I run, ride a bike, take public transport, or drive a car. (Ok, to be more precise, in includi the time to change into sports gear for the bike / running. Without this the bike takes about 30mins. Running does actually take 45 mins run time.)