Current through Register Vol. 28, No. 3, September 1, 2024
Standard:
01
If a shared signal face is provided for a protected/permissive mode left turn,
it shall meet the following requirements (see Figure 4D-11):
A. It shall be capable of displaying the
following signal indications: steady CIRCULAR RED, steady CIRCULAR YELLOW,
CIRCULAR GREEN, steady left-turn YELLOW ARROW, and left-turn GREEN ARROW. Only
one of the three circular indications shall be displayed at any given time.
Only one of the two arrow indications shall be displayed at any given time. If
the left-turn GREEN ARROW signal indication and the CIRCULAR GREEN signal
indication(s) for the adjacent through movement are always terminated together,
the steady left-turn YELLOW ARROW signal indication shall not be
required.
B. During the protected
left-turn movement, the shared signal face shall simultaneously display a
left-turn GREEN ARROW signal indication and a circular signal indication that
is the same color as the signal indication for the adjacent through lane on the
same approach as the protected left turn.
C. A steady left-turn YELLOW ARROW signal
indication shall be displayed following the left-turn GREEN ARROW signal
indication, unless the left-turn GREEN ARROW signal indication and the CIRCULAR
GREEN signal indication(s) for the adjacent through movement are being
terminated together. When the left-turn GREEN ARROW and CIRCULAR GREEN signal
indications are being terminated together, the required display following the
left-turn GREEN ARROW signal indication shall be either the display of a
CIRCULAR YELLOW signal indication alone or the simultaneous display of the
CIRCULAR YELLOW and left-turn YELLOW ARROW signal indications.
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D. During the permissive left-turn movement,
the shared signal face shall display only a CIRCULAR GREEN signal
indication.
E. A
protected/permissive 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.
F. A supplementary sign shall not be
required. If used, it shall be a LEFT TURN YIELD ON GREEN (symbolic circular
green) (R10-12) sign (see Figure 2B-27).
02 If a separate left-turn signal face is
being operated in a protected/permissive left-turn 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 protected/permissive left-turn mode and a flashing
left-turn yellow arrow signal indication is provided, it shall meet the
following requirements (see Figure 4D-12):
A.
It shall be capable of displaying the following signal indications: steady
left-turn RED ARROW, steady left-turn YELLOW ARROW, flashing left-turn YELLOW
ARROW, and left-turn GREEN ARROW. Only one of the four indications shall be
displayed at any given time.
B.
During the protected left-turn movement, a left-turn GREEN ARROW signal
indication shall be displayed.
C. A
steady left-turn YELLOW ARROW signal indication shall be displayed following
the left-turn GREEN ARROW signal indication.
D. During the permissive left-turn movement,
a flashing left-turn YELLOW ARROW signal indication shall be
displayed.
E. A steady left-turn
YELLOW ARROW signal indication shall be displayed following the flashing
left-turn YELLOW ARROW signal indication if the permissive left-turn movement
is being terminated and the separate left-turn signal face will subsequently
display a steady left-turn RED ARROW indication.
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F. 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.
G. When a permissive
left-turn movement is changing to a protected left-turn movement, a left-turn
GREEN ARROW signal indication shall be displayed immediately upon the
termination of the flashing left-turn YELLOW ARROW signal indication. A steady
left-turn YELLOW ARROW
signal indication shall not be displayed between the
display of the flashing left-turn YELLOW ARROW signal indication and the
display of the steady left-turn GREEN ARROW signal indication.
H. The display shall be a four-section signal
face except that a three-section signal face containing a dual-arrow signal
section shall be permitted where signal head height limitations (or lateral
positioning limitations for a horizontally-mounted signal face) will not permit
the use of a four-section signal face. The dual-arrow signal section, where
used, shall display a GREEN ARROW for the protected left-turn movement and a
flashing YELLOW ARROW for the permissive left-turn movement.
I. 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.
J. 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.
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 protected/permissive 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.
B. During the protected
left-turn movement, a left-turn GREEN ARROW signal indication shall be
displayed.
C. A steady left-turn
YELLOW ARROW signal indication shall be displayed following the left-turn GREEN
ARROW signal indication.
D. During
the permissive left-turn movement, a flashing left-turn RED ARROW signal
indication shall be displayed.
E. A
steady left-turn YELLOW ARROW signal indication shall be displayed following
the flashing left-turn RED ARROW signal indication if the permissive left-turn
movement is being terminated and the separate left-turn signal face will
subsequently display a steady left-turn RED ARROW indication.
F. When a permissive left-turn movement is
changing to a protected left-turn movement, a left-turn GREEN ARROW signal
indication shall be displayed immediately upon the termination of the flashing
left-turn RED ARROW signal indication. A steady left-turn YELLOW ARROW signal
indication shall not be displayed between the display of the flashing left-turn
RED ARROW signal indication and the display of the steady left-turn GREEN ARROW
signal indication.
G. 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.
H. 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).
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
protected/permissive mode left-turn movements.
