In the near future, you can have both with the Pibal. The French carmaker Peugeot and designer Philippe Starck have developed this vehicle which can function either way. It was their submission to a contest by the city of Bordeaux to design an urban bike.
Starck sees the Pibal as ideal for this environment. In congested traffic, the user can move slowly as a scooter. When there's more room, the user can ride it as a bicycle. Bright yellow tires make it more visible and a heavy rack in the rear can be used for storage. You can see more photos of it at Dezeen.