Where bike use for transportation is more prevalent, such that great numbers of people riding bikes were commonly riding together, it could make sense for groups of them to pass through an intersection as a unit, rather than one by one. That seems to ask a question such as 'What number of people on bikes in formation can comfortably ride in the footprint of a compact or mid-size car'. People on bikes riding three abreast, two rows...six bikes.

If the people riding bikes were familiar with riding in this kind of close formation, other road users wouldn't have to wait any longer for six people on bikes to pass through an intersection than they would a single car. Whether that kind of practice could ever work as standard procedure is a bigger question.