Fable
Driver tier system
In Qingshi Town, going out depended entirely on cart drivers. The town office divided drivers into five grades: grade one only pulled the reins on the guest's command; grade two knew the common roads; grade three could avoid pits and yield to water; grade four could handle most of the journey on their own and only asked the guest to take over on dangerous slopes; grade five, from accepting the order to delivery, almost never needed prompting.
Car dealerships also love hanging up new signs. Some say they have cruise control, so speed can be held steady; some say they can follow the car ahead; some say they can park themselves in the shed at the door. To customers, they all sound like "can drive itself," and when the price is low, they rush to order.
A stranger hired a low-grade driver with a fixed-speed pedal, thinking he could relax and enjoy the scenery. On the uphill slope the pedal still moved at flat-road speed, and the carriage nearly slid backward. Another guest hired a fourth-class driver; the carriage had no fancy mechanisms, yet it steadily went around the landslide after the rain.
The carriage shop initially mixed the two kinds of talk: having a certain mechanism implied the driver was more skilled; a high driver grade was used to sell a certain mechanism. After several close calls, customers discovered that the mechanism only helped with a certain segment of action, while the grade described who was responsible for the entire route.
The town office first required all carriage companies to write the mechanism names larger. The result was more confusion: the signboards were covered with "steady speed", "follow the carriage" and "enter the shed", yet customers still did not know when they had to take the reins themselves. After a nighttime rain accident, the office finally moved the problem from the signboards to the boundaries of responsibility.
The new plaque was divided into two columns: the left listed carriage tiers, explaining who was responsible under which road conditions; the right listed available mechanisms, explaining which segment of action each mechanism handled, when it expired, and who took over after expiry. When booking a carriage, guests first asked about the tier, then checked whether the mechanisms could save effort.
From then on, being able to hold the reins steady did not mean being able to complete the mountain road alone; being able to enter the shed by itself did not mean it could handle a landslide. Features can help the driver, but levels answer who bears the responsibility. Only by keeping the two things distinct can you avoid mistaking a good footboard for the safety of the whole journey.
Later, the carriage shop learned the order of introduction: first state which class of responsibility this trip belongs to, then describe which mechanisms assist. Customers also learned to ask one question: if the mechanism cannot see the pothole, who takes over? Once that question was asked, many exaggerated signboards fell silent.