Shorter trips may actually be faster by bike if you factor in easier parking. Driving a car is expensive and pollutes the environment. If you ride your bicycle, the cost is next to nothing and you won't be making it harder to breathe. Just think how much you would save if you started doing some of your errands by bike. Using your commute time as workout time can help you, too.
Regular exercise is one of the best ways to stay in shape.
By now you might be wondering what it would take to give bicycle commuting a try. It is probably easier than you think. If you already own a bicycle, you're set to go. A few modifications to your bicycle will make commuting easier. During most of the year you will want to have beefy tires with a smooth tread.