Regulations of Connecticut State Agencies
Basic displays used in signal operations are the steady circular red, circular yellow or circular green indication, used on each of the approaches. The application for these signal indications shall be as follows:
(a) A steady circular red indication:
(1) Shall be given when it is intended to prohibit traffic, except pedestrians directed by a pedestrian signal, from entering the intersection or other controlled area.
(2) May be displayed with the appropriate green arrow indications when it is intended to permit traffic to make a specified turn or turns and to prohibit traffic from proceeding straight ahead through the controlled area. This display is not required where it is physically impossible for traffic to go straight ahead, as at the head of a "T" intersection.
(b) A steady circular yellow indication:
(1) Shall be given following a circular green indication in the same signal face, except if the signal face controls an exclusive left-turn lane and the circular green indication is to be followed by a green arrow indication.
(2) Is an optional alternative to a yellow arrow indication following a green arrow indication in a separate signal face used exclusively to control a single directional movement.
(c) A steady circular green indication shall be given only when it is intended to permit traffic to proceed in any direction which is lawful and practical.
(d) Steady red arrow, yellow arrow and green arrow indications may be used in lieu of the corresponding circular indications at the following locations:
(1) On an approach intersecting a one-way street.
(2) Where certain movements are prohibited.
(3) Where certain movements are physically impossible.
(4) On an intersection approach which has an exclusive lane for turning movements.
(5) Where turning movements are "protected" from conflicting movements by other indications or by the signal sequence.
(6) Where all the movements on the approach do not begin or end at the same time and where the indications for the turning movements will also be visible to trade with other allowable movements.
(e) Steady arrow indications are used as follows:
(1) A steady yellow arrow indication shall be used following a green arrow indication which has been displayed simultaneously with a circular red indication in the same signal face, except in the following case. When a green right turn arrow (or left turn arrow displayed to one-way traffic) is followed immediately by a circular green indication shown alone, during which time no prohibitions are in effect for the indicated turn, the yellow arrow display is not desirable.
(2) A steady yellow arrow indication or optional circular yellow shall follow a green arrow indication in a signal face which is used exclusively to control a single directional movement.
(3) A steady yellow arrow indication may be used to indicate the clearance interval following the termination of a green arrow indication which has been displayed simultaneously with a continuing circular green indication in the same signal face.
(4) A steady green arrow indication shall be used only to allow vehicular movements which are completely protected from conflict with other vehicles moving on a green indication or with pedestrians crossing in conformance with a "Walk" or flashing "Don't Walk" indication.
(5) A steady left green arrow indication shall be used as the green display on a signal face which controls an exclusive left turn lane, if that left turn movement is protected by the signal sequence.
(f) The following combinations of signal indications shall not be simultaneously displayed on any one signal face:
(1) Circular green with circular yellow.
(2) Straight-through green arrow with circular red.
(3) Circular red with circular yellow.
(4) Circular green with circular red.
(g) The above combinations shall not be simultaneously displayed in different signal faces on any one approach unless:
(1) One of the faces is a turn signal controlling only an exclusive turn lane and a sign "Left" or "Right Turn Signal" is located adjacent to each such signal face.
(2) One of the faces is a turn signal controlling only an exclusive turn lane and consists entirely of arrow indications.
(3) The signal faces are shielded, hooded, louvered, positioned or designed so that the combination is not confusing to approaching drivers.
(h) When a traffic control signal is put on flashing operation, normally a yellow indication should be used for the major street and a red indication for the other approaches. Yellow indications shall not be used for all approaches. The following applications shall apply whenever signals are placed on flashing operation:
(1) A circular yellow indication shall be flashed instead of any yellow arrow indication which may be included in that signal face.
(2) No circular green or green arrow indication or flashing yellow indication shall be terminated and immediately followed by a steady red or flashing red indication without the display of the steady yellow change indication; however, transition may be made directly from a circular green or green arrow indication to a flashing yellow indication.
(3) All signal faces on an approach shall flash the same color, either yellow or red (circular or arrow), except that separate signal faces for separately controlled turn movements may flash the other color. The requirements of other sections of these regulations regarding shielding or positioning of conflicting displays apply to flashing indications as well as steady indications. The flashing yellow signal indication for through traffic does not have to be shielded or positioned to prevent visual conflict for drivers in the left turn lane.
(Effective November 3, 1981; Amended December 9, 1999)