As the cost of fuel rises, some police departments are dusting off their bikes and turning to pedal power.

Some departments encourage more foot patrols, while others discourage officers from letting their engines idle or making them travel in twos.

In Bedford, Virginia, the police department bought eight bikes last year and is now saving 200 to 400 gallons of fuel per month. Lieutenant Jim Bennett is in charge of the department's bike unit, and he says the benefit is twofold: cost savings and increased police visibility.

Bike patrols do have limitations. Weather can be a problem and they also can't be used to transport suspects or engage in vehicle chases.

But advocates say the benefits of cost savings and public visibility are worth it. Bikes also can go places cars can't.