If it is difficult to pass on the slopes marked with the appropriate sign, you must give way

Explanation

The vehicle going uphill.

On a steep gradient marked with the corresponding sign, where the road is too narrow for two vehicles to pass at once, priority belongs to the vehicle travelling uphill. The driver going downhill must stop and give way.

The engineering reason matters more than memorising the rule: a vehicle stopped on an incline has to restart on the slope, may roll backwards, and on a narrow mountain road that is a real risk. A vehicle heading downhill can stop and move off again at almost no cost. So the burden is placed on the driver for whom stopping is cheaper.

This rule sees daily use on Armenia's mountain roads.

Why the other answers are wrong

• To a vehicle going downhill — This is the rule reversed: the downhill vehicle gives way, it does not receive priority.
• To a public vehicle — Being a public service vehicle grants no priority here; the only criterion is the direction of the slope.