An all-way stop is an intersection

Intersection (road)

An intersection is a road junction where two or more roads either meet or cross at grade . An intersection may be 3-way - a T junction or fork, 4-way - a crossroads, or 5-way or more...

 system used predominantly in the United States of America, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 and South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

 where traffic

Traffic

Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel...

 approaching it from all directions is required to stop before proceeding through the intersection. An all-way stop may have multiple approaches and may be marked with a supplemental plate stating the number of approaches.

Operation

A motorist approaching an all-way stop is always required to come to a full stop before the crosswalk or stop line. In most jurisdictions that use all-way stops, pedestrians always have priority at a crosswalk

Pedestrian crossing

A pedestrian crossing or crosswalk is a designated point on a road at which some means are employed to assist pedestrians wishing to cross. They are designed to keep pedestrians together where they can be seen by motorists, and where they can cross most safely across the flow of vehicular traffic...

, even if the crosswalk is not delineated with pavement marking

Road surface marking

Road surface marking is any kind of device or material that is used on a road surface in order to convey official information. They can also be applied in other facilities used by vehicles to mark parking spaces or designate areas for other uses....

s. Within some US jurisdictions, such as the state of Idaho

Idaho

Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....

, bicyclists are exempt from the need to make a complete stop, but must give way to other vehicles as otherwise required by law. After a full-stop has been made, vehicles usually have the right-of-way to proceed through the intersection in the order that they arrived at the intersection. In the USA, if vehicles arrive at approximately the same time, each driver must yield to the drivers on their right, while in South Africa drivers must use common sense and make eye contact

Eye contact

Eye contact is a meeting of the eyes between two individuals.In human beings, eye contact is a form of nonverbal communication and is thought to have a large influence on social behavior. Coined in the early to mid-1960s, the term has come in the West to often define the act as a meaningful and...

 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.

Application

In the USA the Federal Highway Administration Federal Highway Administration The Federal Highway Administration is a division of the United States Department of Transportation that specializes in highway transportation. The agency's major activities are grouped into two "programs," the Federal-aid Highway Program and the Federal Lands Highway Program... 's Manual on Uniform Traffic Control Devices Manual on Uniform Traffic Control Devices The Manual on Uniform Traffic Control Devices is a document issued by the Federal Highway Administration of the United States Department of Transportation to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used... (MUTCD) defines the standards commonly used for the application of all-way stops. Where a stop has been determined to qualify, it is signed at all intersections with a standard octogonal "Stop" sign, with one of two secondary signs placed below the stop sign. In the case of an intersection with 4 points, optionally a "4 Way" secondary sign may be placed below the stop sign. An "All Way" secondary sign may be placed at a 4-way stop, and an "All Way" secondary sign only must be used where there are other than four points meeting at the intersection and all points have a stop sign. According to the MUTCD, installation of an all-way stop should be based on a traffic engineering Traffic engineering Traffic engineering can mean:* traffic engineering , a branch of civil engineering* teletraffic engineering, a field of statistical techniques used in telecommunications...  study to determine if minimum traffic volume or safety criteria are met. These intersections are often found where roads with considerably equal traffic levels meet each other but the overall level of traffic present at the intersection does not justify a traffic light Traffic light Traffic lights, which may also be known as stoplights, traffic lamps, traffic signals, signal lights, robots or semaphore, are signalling devices positioned at road intersections, pedestrian crossings and other locations to control competing flows of traffic... , and or in a location where the right of way was otherwise unclear. An all-way stop may also be justified if the intersection has a demonstrated history of crash Car accident A traffic collision, also known as a traffic accident, motor vehicle collision, motor vehicle accident, car accident, automobile accident, Road Traffic Collision or car crash, occurs when a vehicle collides with another vehicle, pedestrian, animal, road debris, or other stationary obstruction,... es in a given period of a type susceptible to correction by installing an all-way stop. All-way stops may also be used as an interim measure preceding the placement of a traffic light, to provide a low-speed area for pedestrians to cross, where a cross street experiences considerable difficulty finding safe gaps due to heavy traffic volumes, or where traffic is frequently delayed by turning conflicts. Additionally the MUTCD advocates the placement of all-way stops at intersections between through roads in residential areas if an engineering study can show that traffic flow Traffic flow Traffic flow, in mathematics and civil engineering, is the study of interactions between vehicles, drivers, and infrastructure , with the aim of understanding and developing an optimal road network with efficient movement of traffic and minimal traffic congestion problems.-History:Attempts to...  would be improved by installing the all-way stop control. Despite published guidelines, all-way stops are routinely placed by jurisdictions due to political pressure from adjacent residents. Intersections between two minor highway Highway A highway is any public road. In American English, the term is common and almost always designates major roads. In British English, the term designates any road open to the public. Any interconnected set of highways can be variously referred to as a "highway system", a "highway network", or a... s with similar traffic counts, two collector road Collector road A collector road or distributor road is a low to moderate-capacity road which serve to move traffic from local streets to arterial roads. Unlike arterials, collectors are also designed to provide access to residential properties... s in an urban or suburban setting or a collector road and a local road in a busy setting (such as near a school) are the most common locations for an all-way stop.

Traffic signals will sometimes flash red indications in all directions following a malfunction, or all-red flashing operation may be scheduled to reduce delay or handle construction activity or unusual traffic patterns. When a traffic signal flashes in all-red mode, it legally operates as an all-way stop. When all approaches to an intersection are controlled in this way the rules for an all-way stop apply. However, it must also be noted that traffic signals may also flash yellow to major directions and flash red to minor directions during off-peak times to minimize traffic delays, in which case only side-street traffic is required to stop and yield the right of way to crossing traffic on the major street.

During electrical outages when a traffic signal does not display any indications including flashing red, some jurisdictions require that the intersection be treated as an all-way stop. Other jurisdictions treat a dark signal as an uncontrolled intersection, where standard rules of right-of-way apply without the requirement of a complete stop.

Benefits and disadvantages

The main reason for the use of stops signs at road junctions is safety. According to an international study of locations where the system is in use, all-way stop control applied to four-legged intersections may reduce accident occurrence by 45%. However, given alternative methods of intersection control and some of the disadvantages of all-way stops, the Handbook of Road Safety Measures recommends that four-way stops are best used between minor roads away from urbanized areas. Some of the other benefits of all-way stops are:

• equal priority for all approaches, which can reduce delays to side-street approaches that would otherwise need to wait for a safe gap.

• assurance that vehicles enter the intersection at a low speed and have more time to take heed of the traffic situation, especially useful when sight distance is highly restricted.

• provision of a low-speed crossing point for pedestrians.

• often used as the default behaviour when traffic signals fail, allowing a reasonable traffic flow.

Some of the disadvantages associated with all-way stops are:

• increased emissions of hydrocarbon
  Hydrocarbon
  In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
  
  s.

• increased average delay.

• that once installed stop signs in general are unsafe to remove, accidents that result in injury may increase by 40%. Once an all-way stop is installed, removal is difficult and risky, as habitual drivers may continue to expect an all-way stop condition.

• wasted fuel and vehicle wear by requiring all drivers to stop, even when conflicting traffic is not present.

• worsened delays at adjacent intersections by causing traffic to leave the intersection equally spaced.

• obstructions to traffic that would not otherwise exist, increasing the risk of rear-end crashes.

• reduced respect for stop signs if drivers perceive a complete stop to be unnecessary in the absence of conflicting traffic.

Worldwide comparisons

Most countries outside North America, particularly in Europe, rarely have intersections where all users must stop at all times; the conditions for stop sign

Stop sign

A Stop sign is a traffic sign to notify drivers that they must stop before proceeding.-Specifications:The Vienna Convention on Road Signs and Signals proposed standard stop sign diameters of 0.6, 0.9 or 1.2 metres. UK and New Zealand stop signs are 750, 900 or 1200 mm, according to sign...

 placement may preclude such an arrangement in many places. In Sweden

Sweden

Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

 all-way stops (Flervägsstopp) have been tested since the 1980s but are little used even though they are now permitted.

At four-legged intersections within Europe, it is usual for one road to be given priority over the other, or for a roundabout

Roundabout

A roundabout is the name for a road junction in which traffic moves in one direction around a central island. The word dates from the early 20th century. Roundabouts are common in many countries around the world...

 or mini-roundabout to be used to assign a relative priority to each approach. (This latter solution remains rare in North America, where early failures of rotaries and traffic circles caused such designs to lose favour until the gradual introduction of the modern roundabout in the late 20th century.)