7C. Traffic Signal Design

Question 1

Where can a Vertical Signal Face design be found

Answer 1

MUTCD Chapter 4, Section 4D.09

Question 2

What are the Typical Arrangements of Signal Sections in Signal Faces That Do Not Control Turning Movements for a vertical signal face

Answer 2

MUTCD Chapter 4
R
Y
G (or green arrow)

Figure 4D-2

Question 3

What are the Typical Arrangements of Signal Sections in Signal Faces That Do Not Control Turning Movements for a horizontal signal face

Answer 3

MUTCD Chapter 4

R Y G (or green arrow)

Could also be

R R Y G

Figure 4D-2

Question 4

The relative positions of signal sections in a vertically-arranged signal face, from top to bottom, shall be as follows:

Answer 4

MUTCD Chapter 4: Section 4D.09

CIRCULAR RED
Steady and/or flashing left-turn RED ARROW
Steady and/or flashing right-turn RED ARROW
CIRCULAR YELLOW
CIRCULAR GREEN
Straight-through GREEN ARROW
Steady left-turn YELLOW ARROW
Flashing left-turn YELLOW ARROW
Left-turn GREEN ARROW
Steady right-turn YELLOW ARROW
Flashing right-turn YELLOW ARROW
Right-turn GREEN ARROW

Question 5

The relative positions of signal sections in a horizontally-arranged signal face, from left to right, shall be as follows:

Answer 5

MUTCD Chapter 4: Section 4D.10

CIRCULAR RED
Steady and/or flashing left-turn RED ARROW
Steady and/or flashing right-turn RED ARROW
CIRCULAR YELLOW
Steady left-turn YELLOW ARROW
Flashing left-turn YELLOW ARROW
Left-turn GREEN ARROW
CIRCULAR GREEN
Straight-through GREEN ARROW
Steady right-turn YELLOW ARROW
Flashing right-turn YELLOW ARROW
Right-turn GREEN ARROW

Question 6

What is the minimum and maximum height for the signal housing for any portion of a highway.

Answer 6

MUTCD Chapter 4: Section 4D.15 Mounting Height of Signal Faces

The bottom of the signal housing and any related attachments to a vehicular signal face located over any portion of a highway that can be used by motor vehicles shall be at least 15 feet above the pavement.

The top of the signal housing of a vehicular signal face located over any portion of a highway that can be used by motor vehicles shall not be more than 25.6 feet above the pavement.

Question 7

What is the minimum height the bottom of the signal housing (including brackets) of a vehicular signal face that is vertically
arranged and not located over a roadway:

Answer 7

MUTCD Chapter 4: Section 4D.15 Mounting Height of Signal Faces

A. Shall be a minimum of 8 feet and a maximum of 19 feet above the sidewalk or, if there is no sidewalk, above the pavement grade at the center of the roadway.

B. Shall be a minimum of 4.5 feet and a maximum of 19 feet above the median island grade of a center median island if located on the near side of the intersection.

Question 8

What is the minimum height the bottom of the signal housing (including brackets) of a vehicular signal face that is horizontally
arranged and not located over a roadway:

Answer 8

MUTCD Chapter 4: Section 4D.15 Mounting Height of Signal Faces

A. Shall be a minimum of 8 feet and a maximum of 22 feet above the sidewalk or, if there is no sidewalk, above the pavement grade at the center of the roadway.

B. Shall be a minimum of 4.5 feet and a maximum of 22 feet above the median island grade of a center median island if located on the near side of the intersection.

Question 9

What is a dilemma zone

Answer 9

P.E. Handbook 5.4
Adilemma zone is defined as a zone within which a driver can neither bring his/her vehicle to a stop safely nor go through the signal­controlled intersection before the signal turns red.