It would be useful to be able to click a rider in the names list, and mark them as special in some way. It might be “buddy”, or “rider leader” for example.
These would then be shown on a profile indicator along with yourself. This would make it easier for group riders to know if they have got a long way ahead of the ride leader, are behind the tail sweeper etc.
The indicators would only show for individuals who have set them, of course, since people might select different people.
The indicators could also hover over the avatar on the road.
I’ve illustrated the idea here (bottom left, shows me, sweeper in red and leader in green):http://i.imgur.com/CLst1ab.jpg