Priority to the right

Priority to the right is a right-of-way system, in which the driver of a vehicle is required to give way to vehicles approaching from the right at intersections. The system is stipulated in Article 18.4.a of the Vienna Convention on Road Traffic for countries where traffic keeps to the right and applies to all intersections where it is not overridden by priority signs (uncontrolled intersections), including side roads and roundabouts (but not paths or earth-tracks).

The system is widely used in countries with right-hand traffic, including most European countries. What varies, however, is the prevalence of uncontrolled intersections. In some countries, the right of way at virtually all but the most minor road junctions is controlled by the display of priority vs. stop / yield signs or by traffic lights, while in others (such as France) priority-to-the-right is sometimes applied even at heavily trafficked intersections such as the Place de l'Étoile (around the Arc de Triomphe) and on the Boulevard Périphérique (Paris ring road).

Most states in the United States enforce priority-to-the-right at uncontrolled intersections, where motorists must yield to the right, although these intersections are less common. Increasingly, municipalities across the US have introduced all way stops, traffic signals and other designations such as multiple lane right-of-way or paved vs. unpaved roads as a means of controlling the intersections to decrease the likelihood of a collision and to make it easier to determine liability in the event of an accident. At T-Intersections, traffic on the terminating road must yield to all traffic at the termination point.

Some countries use the priority-to-the-right rule, despite driving on the left. Australia uses the priority-to-the-right rule at four-way intersections where the roads all have equal priority, but specific rules apply for T-intersections. Most intersections are marked and signed however, so this rule is mostly applied at intersections with failed traffic lights.Singapore also uses priority-to-the-right, as well as priority to vehicles going straight and turning vehicles to give way to vehicles going straight.

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Wikipedia