The Gaz-67b is a vehicle designed solely for transportation, they were general purpose 4-wheel drives made by the Soviet Union during WWII.
 In Game
In Call of Duty: United Offensive, the Gaz-67b is the Soviet Union's main transportation vehicle. It can hold three people; a driver, a gunner and a passenger. Just watch out for tanks and enemies with anti-tank weapons; they'll destroy you in no time flat.
If you feel like using it as a taxi, get in and honk the horn. That usually attracts somebody that needs a ride. When they get in, ask them where they want to go and drive them there.