October 2, 2003 97-R-1168
TO:
FROM: James J. Fazzalaro, Principal Analyst
RE: Four-way Stop Signs
You asked what the law specifies about the use of four-way stop signs, if they are common in most towns, and if there are any restrictions on their use.
SUMMARY
State law gives local traffic authorities power to determine through streets and erect stop signs at the intersecting streets. It also specifies that these authorities are not prevented by the law from erecting stop signs at all the corners of an intersection. State Traffic Commission (STC) regulations specify the size, form, placement, and other things relative to stop signs and other types of traffic control devices. These regulations reflect the requirements of the Manual on Uniform Traffic Control Devices (MUCTD), a set of national standards promulgated by the Federal Highway Administration to which all traffic authorities must subscribe. The purpose of these national standards is to insure uniform traffic regulation throughout the United States.
Intersections with four-way stop signs are not unusual, although the towns do not maintain precise inventory lists that would allow easy access to exact numbers. It is a common practice by many local authorities to use them at locations where traffic volumes may not warrant the use of traffic lights. State regulations and the MUCTD specify that at any multi-way stop intersection, supplemental plates should be attached below the stop sign that state it is a “all-way” or (in the case of an intersection with four approaches) a “four-way” stop. In practice, these supplemental plates are not always found at multi-way stop intersections, possibly because of the extra costs associated with providing them.
The MUCTD specifies certain conditions that generally warrant consideration of using a multi-way stop sign installation. One is an accident history of at least five accidents in a 12-month period of a type that can possibly be corrected by an installation of this type.
STATE LAW
State law gives a municipality's legal traffic authority the power to designate any road under its jurisdiction as a through road and to erect stop signs at any such intersection for purposes of controlling traffic. (Depending on the particular form of town government, a local traffic authority by law can be a board of police commissioners, a city or town manager, the chief or superintendent of police, any legally elected or appointed board, any official having similar powers and duties, or the board of selectmen.) Stop signs erected to control crossing traffic must bear the word “stop”, be self-illuminating at night or placed in such a way that they are illuminated by a street light or vehicle headlights, be located as near as practical to the traveled portion of the highway at the entrance to which traffic is to stop, and be clearly visible from a distance of 100 feet along the street intersecting the through way (CGS § 14-301).
A motorist must stop in obedience to a stop sign at the stop line the traffic authority may establish adjacent to the stop sign, or if there is no stop line, at the entrance to the through highway, and must “yield the right-of-way to vehicles not so obliged to stop which are within the intersection or approaching so closely as to constitute an immediate hazard” (CGS § 14-301 (c)). The law further states that its provisions do not prevent a traffic authority “from erecting such stop signs on all corners of any intersection within its jurisdiction” and when this happens the above requirements relative to stopping and granting right-of-way for vehicles at stop signs at through streets apply to vehicles on each of the intersecting streets.
Another law, not directly related to the requirements for stopping at stop signs, but relevant to the proper flow of traffic through intersections specifies that any driver approaching an intersection must grant the right-of-way to any vehicle approaching from his right when the vehicles are arriving at the intersection at approximately the same time (CGS § 14-245).
STATE REGULATIONS
STC regulations regarding stop signs generally reflect the requirements of the MUTCD. This is a national code of uniform standards for traffic control devices that governs things like traffic lights, signs, pavement markings, sign placing and spacing, and other matters. It assures that traffic control throughout the country will be uniform in that states must follow the guidelines for the traffic control devices they employ. For example, MUCTD specifies the standard lettering (STOP), color (white letters and border on a red background), shape (octagonal), and size of stop signs. STC regulations state that the standard size of a stop sign is 30x30 inches: when greater emphasis or visibility is required a larger size is recommended; and on low-volume local streets and secondary roads with low approach speeds a sign that is 24x24 inches can be used. These reflect specifications of the MUCTD.
As required by the MUCTD, the state regulations specify that at a multi-way stop intersection, a supplementary plate should be mounted just below each stop sign. If the number of approach legs to the intersection is three or more, the numeral on the plate must correspond to the number of approaches or the legend “ALL-WAY” may be used instead. The plate must be white lettering on red background and must be a standard size of 12x6 or 18x6 inches (State Agencies Regs. § 14-298-522).
Some of the other regulatory requirements that reflect the MUCTD include:
1. not using stop signs on through roads or expressways;
2. not erecting them at intersections where traffic control signals are operating;
3. unless traffic engineering studies justify another decision, normally posting the stop signs on the main intersecting highway that has the lesser flow of traffic;
4. using portable stop signs only for emergencies;
5. not using stop signs for speed control;
6. erecting a stop sign at the point where the vehicle is supposed to stop and, if desirable, supplementing it with a stop line, the word “stop” on the pavement, or both;
7. if two lanes of traffic are subject to the stop sign, placing a second sign where it is visible to traffic on the inner lane; and
8. if visibility of a stop sign is restricted, placing a “STOP AHEAD” sign in advance of the stop sign.
WHEN ALL-WAY STOPS ARE APPROPRIATE
When deciding on what types of traffic control devices are appropriate in different situations, traffic engineers follow a process of determining the “warrants” for a particular situation. They essentially apply generally accepted traffic engineering principles to the specific circumstances to decide whether the location “warrants” that particular traffic control device. The MUCTD provides a general list of warrants for each type of application, but local officials have some discretion in these matters.
The MUCTD states that multi-way stops should ordinarily be used only where traffic volume on the intersecting roads is approximately equal. A traffic signal is considered more satisfactory for intersections with high traffic volumes. It further states that a multi-way stop installation may be warranted:
1. as an easily installed interim measure where traffic signals are urgently needed;
2. where there is an accident problem evidenced by five or more reported accidents of a type susceptible to correction by a multi-way stop (such as right and left turn accidents and right angle accidents) in a 12-month period; or
3. where total traffic volume entering the intersection from all directions averages at least 500 vehicles per hour for any eight hours of an average day and combined vehicle and pedestrian volume for the minor street averages at least 200 units per hour for the same eight hours, with an average delay to minor street vehicular traffic of at least 30 seconds per vehicle during the maximum hour. When the 85th percentile approach speed of the major street traffic exceeds 40 miles per hour, the minimum vehicle volume warrant is 70% of these requirements. (MUCTD, 1988 Ed., § 2B-6). The 85th percentile speed is the speed at which 85% of the vehicles in the traffic flow are traveling.
JJF:pa