A shared taxi leaves when it is full, and that is the whole timetable

Departure on load is a different scheduling principle

A scheduled service runs whether it is full or empty, and the operator carries the risk of the empty seats. A shared vehicle inverts that: it waits until the seats are sold and only then sets off, which transfers the risk of low demand from the driver to the passengers sitting in the vehicle.

The consequence is that the wait is a function of demand rather than of a timetable. On a busy route between two large towns the vehicle may fill in ten minutes; on a thin route it can take hours, and it may not fill at all after the middle of the afternoon.

This also explains the well-known pattern of leaving early. Shared transport is busiest in the first hours of the day because that is when local traffic moves, so the traveller who arrives at seven finds a nearly full vehicle and the one who arrives at four in the afternoon may find an empty one.

The station is a market, and it is organised by destination

The place these vehicles gather is usually a yard rather than a terminal, and it is organised by destination rather than by departure time. Vehicles line up in the order they arrived, and the one at the front of its line is the one currently filling, which is the single most useful thing to understand on walking in.

Touts and agents work these yards, and their role is genuinely mixed. Some are employed to fill vehicles and will steer you correctly because that is how they are paid; others are selling a seat on a vehicle that will not leave for a long time, and the difference isn’t visible from outside.

Asking how many seats are still empty is usually more informative than asking when it leaves. The answer to the second question is almost always soon, whereas the answer to the first is checkable by looking, and it tells you what the wait will actually be.

Price is often fixed, and the negotiation is about something else

It is a common assumption that fares in this system are haggled. Frequently they aren’t. Many routes have a customary or officially posted fare per seat that everyone locally knows, and the price is stable enough that asking a fellow passenger is a reliable way to learn it.

What is genuinely variable is everything around the seat: luggage on the roof or in the boot, an extra charge for a large bag, the price of buying two seats so that three people do not share a bench built for two, and the cost of chartering the whole vehicle so it leaves immediately.

That last option is worth knowing about because it is the release valve of the entire system. If the wait has become intolerable, the remaining seats can usually be bought, and the vehicle then goes. Whether that is extravagant or sensible depends on how many hours of daylight are left.

Comfort, capacity and the seat that is worth choosing

Capacity in shared transport is a social convention rather than a fixed number, and the same vehicle may be considered full at different loads on different routes. Rows are shared closely, luggage travels on the roof or under feet, and the journey is more physically demanding than its distance suggests.

Seat position matters more than it does on a bus. The front row usually offers more room and better air, the rear is bumpiest, and the middle of a bench between two other passengers is the seat nobody chooses. Arriving early buys the choice as well as the earlier departure.

Stops happen on demand rather than at stations. People are set down at junctions, farm tracks and roadside stalls, which is why the journey time quoted by a driver is optimistic and why the vehicle that seemed direct turns out to be serving every settlement along the way.

Where this system is strong and where it is weak

Its strengths are real. It reaches places no scheduled operator can serve profitably, it runs at high frequency on busy corridors without any planning apparatus, and it responds to demand within minutes rather than within a timetable revision. In much of the world it is the transport network, and calling it informal understates its coverage.

The weaknesses are equally real. Regulation, insurance and vehicle maintenance vary enormously, drivers are paid by the trip in ways that reward speed, and there is no published record of the service to appeal to when something goes wrong. Night journeys on this kind of transport are widely avoided by locals for reasons worth taking seriously.

For a traveller the sensible approach is to treat it as an ordinary local system with local conventions rather than as an adventure. Travel in the morning, ask other passengers rather than only the driver, keep valuables off the roof, and accept that the departure time is a fact about the load rather than a promise.