Tactics
If lines of sight are long, and both drivers are familiar with the road, vehicles heading towards each other can adjust their speed so as to arrive at a wide spot at the same time and pass slowly, avoiding the need for either vehicle to stop.
When two vehicles meet head-on, generally the drivers confer to decide in which direction lies the closest wide spot, and together they travel there, the lead vehicle necessarily in reverse gear.
In Scotland, where most drivers are accustomed to single-track roads, it is customary for drivers to acknowledge each other with a wave, or flash of headlights at night. Generally in Scotland, if the passing place is to the right-hand side of a vehicle, the driver would never pull in to the passing place to let the other driver pass. Instead the driver would stop just short of the passing place on the road, to leave space for the oncoming vehicle to manouvre into the passing place which would be on their left. At night, if a driver were to see an oncoming vehicle in the distance and was reasonably close to a passing place, the driver would flash the headlights which would signal the other car to proceed forward while either the other vehicle reversed back to a passing place, or waited beside a passing place for the other car to arrive. In the United States, it is customary to move the right hand to the top of the steering wheel, palm down, and raise four fingers.
Usually when there is a brief one-lane bottleneck of a 2-lane road, traffic will usually yield to oncoming traffic already in the bottleneck. One-lane single-track roads usually have no conflict.
Read more about this topic: Single-track Road