Current through Register Vol. 28, No. 3, September 1, 2024
Standard:
01
If a shared signal face is provided for a permissive only mode left turn, it
shall meet the following requirements (see Figure 4D-6):
A. It shall be capable of displaying the
following signal indications: steady CIRCULAR RED, steady CIRCULAR YELLOW, and
CIRCULAR GREEN. Only one of the three indications shall be displayed at any
given time.
B. During the
permissive left-turn movement, a CIRCULAR GREEN signal indication shall be
displayed.
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C. A permissive only shared signal face,
regardless of where it is positioned and regardless of how many adjacent
through signal faces are provided, shall always simultaneously display the same
color of circular indication that the adjacent through signal face or faces
display.
D. If the permissive only
mode is not the only left-turn mode used for the approach, the signal face
shall be the same shared signal face that is used for the protected/permissive
mode (see Section 4D.20) except that the left-turn GREEN ARROW and left-turn
YELLOW ARROW signal indications shall not be displayed when operating in the
permissive only mode.
02
If a separate left-turn signal face is being operated in a permissive only
left-turns mode, a CIRCULAR GREEN signal indication shall not be used in that
face.
03 If a separate left-turn
signal face is being operated in a permissive only left-turn mode and a
flashing left-turn YELLOW ARROW signal indication is provided, it shall meet
the following requirements (see Figure 4D-7):
A. It shall be capable of displaying the
following signal indications: steady left-turn RED ARROW, steady left-turn
YELLOW ARROW, and flashing left-turn YELLOW ARROW. Only one of the three
indications shall be displayed at any given time.
B. During the permissive left-turn movement,
a flashing left-turn YELLOW ARROW signal indication shall be
displayed.
C. A steady left-turn
YELLOW ARROW signal indication shall be displayed following the flashing
left-turn YELLOW ARROW signal indication.
D. It shall be permitted to display a
flashing left-turn YELLOW ARROW signal indication for a permissive left-turn
movement while the signal faces for the adjacent through movement display
steady CIRCULAR RED signal indications and the opposing left-turn signal faces
display left-turn GREEN ARROW signal indications for a protected left-turn
movement.
E. During steady mode
(stop-and-go) operation, the signal section that displays the steady left-turn
YELLOW ARROW signal indication during change intervals shall not be used to
display the flashing left-turn YELLOW ARROW signal indication for permissive
left turns.
F. During flashing mode
operation (see Section 4D.30), the display of a flashing left-turn YELLOW ARROW
signal indication shall be only from the signal section that displays a steady
left-turn YELLOW ARROW signal indication during steady mode (stop-and-go)
operation.
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G. If the permissive only mode is not the
only left-turn mode used for the approach, the signal face shall be the same
separate left-turn signal face with a flashing YELLOW ARROW signal indication
that is used for the protected/permissive mode (see Section 4D.20) except that
the left-turn GREEN ARROW signal indication shall not be displayed when
operating in the permissive only mode.
Option:
04 A separate left-turn signal face with a
flashing left-turn RED ARROW signal indication during the permissive left-turn
movement may be used for unusual geometric conditions, such as wide medians
with offset left-turn lanes, but only when an engineering study determines that
each and every vehicle must successively come to a full stop before making a
permissive left turn.
Standard:
05 If a separate left-turn signal face is
being operated in a permissive only left-turn mode and a flashing left-turn RED
ARROW signal indication is provided, it shall meet the following requirements
(see Figure 4D-8):
A. It shall be capable of
displaying the following signal indications: steady or flashing left-turn RED
ARROW, steady left-turn YELLOW ARROW, and left-turn GREEN ARROW. Only one of
the three indications shall be displayed at any given time. The GREEN ARROW
indication is required in order to provide a three-section signal face, but
shall not be displayed during the permissive only mode.
B. During the permissive left-turn movement,
a flashing left-turn RED ARROW signal indication shall be displayed, thus
indicating that each and every vehicle must successively come to a full stop
before making a permissive left turn.
C. A steady left-turn YELLOW ARROW signal
indication shall be displayed following the flashing left-turn RED ARROW signal
indication.
D. It shall be
permitted to display a flashing left-turn RED ARROW signal indication for a
permissive left-turn movement while the signal faces for the adjacent through
movement display steady CIRCULAR RED signal indications and the opposing
left-turn signal faces display left-turn GREEN ARROW signal indications for a
protected left-turn movement.
E. A
supplementary sign shall not be required. If used, it shall be a LEFT TURN
YIELD ON FLASHING RED ARROW AFTER STOP (R10-27) sign (see Figure 2B-27).
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Option:
06 The requirements of Item A in Paragraph 5
may be met by a vertically-arranged signal face with a horizontal cluster of
two left-turn RED ARROW signal indications, the left-most of which displays a
steady indication and the right-most of which displays a flashing indication
(see Figure 4D-8).
Support:
07 (DE Revision) DelDOT's "Traffic Design
Manual" contains further information regarding signal indications for
permissive only mode left-turn movements.
