Though tro-tros are the cheapest means of transport here, be prepared to experience these problems.
Not by fellow passengers but by touts, there are many people who act as touts here and one can come to you asking you to give them your fare yet there are not the tout for the vehicle you've boarded.
Note: Here people don't purchase bus tickets like in most developed countries, you pay your fare directly to the tout.
What to do: Wait until the vehicle is full and has left the station before you pay, the tout that is on board is the real tout for that vehicle
Animals on board
Don't be too shocked in case the person that sits next to you carries hens or a goat or rabbits on board, this is especially common in vehicles that are going to rural areas, for vehicles that operate within towns, you aren't likely to face this.
What to do: Take the co-driver seat, you'll sit alone and won't have such inconveniences.