An all-way stop is an intersection system used predominantly in the United States of America, Canada and South Africa where traffic approaching it from all directions is required to stop before proceeding through the intersection. Such intersections are most often found in the form of a '4-way stop', but may also sometimes be a '3-way stop' (either if one road ends there or if one street involved is one-way), or a '2-way stop' if both streets are one way or situated at right angles. Where five or more directions of traffic approach such an intersection 'all-way stop' is generally used. 'All-way stop' always implies that all approaches must stop, whereas 'N-way stop' does not necessarily imply this but always serves to indicate the number of approaches that do stop. A stop sign at an all-way stop does not need to have a supplemental plate but often does.
A motorist approaching an all-way stop is always required to come to a full stop. In most jurisdictions that use all-way stops, pedestrians always have priority at a crosswalk, even unmarked ones which exist at every intersection with approximately right angles as the logical continuations of the sidewalks. Bicyclists in some US jurisdictions, such as Idaho, may treat any stop sign as a yield sign. After a full-stop has been made, vehicles usually have the right-of-way to proceed through the intersection in the order that they have stopped at the intersection. In the USA if two or more vehicles arrive at approximately the same time the road user on the left yields to the user on their right , while in South Africa drivers must use common sense and gestures. Some areas have additional formal and informal rules which may or may not include special procedures for when all stop signs are approached simultaneously.
Where this intersection type is used a failed traffic light would usually be considered an all-way stop until police arrive or normal operation is restored. Alternatively, in some jurisdictions that use all-way stops, a failed traffic light is treated as an uncontrolled intersection. When an approach to an intersection is controlled by a red flashing light it is the equivalent of a stop sign in almost every US jurisdiction . When all approaches to an intersection are controlled in this way the rules for an all-way stop apply.
Most countries outside North America, particularly in Europe, simply do not have intersections where all users have to stop whenever they are approached. As the most restrictive type of controlled intersection in North America, the all-way stop's equivalent is realized in a number of ways elsewhere. In countries where 'priority to the right' is observed as a default rule, the most restrictive type of intersection can be an uncontrolled one. It usually only occurs in conjunction with low-volume roads or as a traffic calming device that is similar in terms of desired effect, but not methodology to an all-way stop . An intersection type considered to be complementary (or alternative, depending on location) to the all-way stop and in fact used on six continents, is the roundabout. In particular the UK, amongst others, has adopted the roundabout instead of the all-way stop as the most restrictive type of intersection. There are a number of key differences in approach:
The frequent stopping of vehicles associated with all-way stops reduces their efficiency and increases wear in comparison to the relatively constant speed of a vehicle using roundabouts. This may help to explain the prominence of roundabouts in Europe, where fuel is typically more expensive than in North America.
Except in larger traffic circles, pedestrians are generally not permitted to use the central island of a roundabout. To safely and perhaps legally continue through such intersections a pedestrian may be required take an even longer route than vehicular traffic to utilize pedestrian crossings. As the most restrictive type of intersection all-way stops are often considered the safest type of intersection for such users.
Learner drivers also have difficulty correctly using All-way stops because of their complex rules, which often differ by location, and because they are observed with varying degrees of compliance. One uninformed or aggressive driver can easily disrupt the ideal flow through the intersection, which is not unlikely given the more complex rules for its users and the multitude of possible right-of-way of errors that can be made. Roundabouts do not suffer from such ambiguities. The only possible mistakes one can make in a roundabout are a failure to yield on entry or an unnecessary yield while in the roundabout. The simple rules and physics of a roundabout all but eliminate many of the dangerous movements associated with traditional crossroads; roundabouts command driver respect and are less complex than a all-way stops, but they may give drivers a false sense of security.
Nonetheless, stop signs at large are far more prominent in North America, notably the US, than in countries that do not use all-way stops. The colloquialism that 'familiarity breeds contempt' can help to explain why stop signs are almost universally (in terms of location, not users) disrespected in the US. For example: the criteria for the placement of an all-way stop might only take into account peak conditions, meaning a stop might only be necessary at peak times at an otherwise highly visible intersection. Legally obligated, but ostensibly unnecessary, frequent stopping can indirectly encourage faster and possibly illegal driving between stop signs. A driver traversing mostly roundabouts will, having likely not stopped, not have an incentive to speed and will be more receptive to a stop sign placed for actual safety needs, like because a yield/give way sign is insufficient. Despite the law, stop signs in the US are indeed violated in all manners, usually by simply not completely stopping, what is known as a 'rolling' or 'California' stop amongst other names.