The vehicles were electric battery powered to keep noise to a minimum and not wake people in the very early morning hours.
Delivery by bicycle was unknown in UK. To my knowledge bicycles have never been used as a method of hauling around goods.
Japan is, of course, the diametric opposite, with almost every home having at least one bicycle, which are used heavily, daily, for shopping, taking kids to preschool etc. It's common to see people with kids on the back and front of a bicycle and shopping bags to boot. Battery pack assisted bicycles are so common that they've almost pushed out the old fashioned manual type. We have two, and all our neighbours use power assisted types.
And now, back to films !