The conductor on a trotro, and the interface between you and the system.
The mate:
- Hangs out of the sliding door calling the destination
- Signals the route with a hand gesture — a rotating finger for Circle, a flattened hand for the airport
- Collects fares once the bus is moving, and gives change
- Decides when the bus is full and it is time to go
- Tells you when to get off, if you told them your destination when boarding
Learning the hand signals takes about a week of watching. Asking the mate directly works from day one.