ITE Journal January 2018 - 45

and detector placement. The Type II dilemma zone is widely known
as an area of intersection approach in which the driver has difficulty
in correct decision making to stop or go. The driver may incorrectly
decide to stop when the correct decision is to proceed and vice versa.
Either type may cause an increase in conflicts and crashes.
The primary purpose of the yellow change interval is to
warn drivers that the green interval has terminated and that the
red indication will be displayed next.14 A driver approaching a
signalized intersection has two choices at the onset of the yellow
change interval: (1) come to a stop at the stop line of the intersection
or (2) clear the intersection before the onset of the CR indication.15
The Type I and II dilemma zones are commonly used to explain
driver error in making this choice. The red clearance interval is
considered a factor of safety for collision avoidance for vehicles
that entered the signalized intersection at the last moment of the
yellow change interval. The aim of yellow change and red clearance
intervals is to provide safe transition between all conflicting traffic
movements at signalized intersections.
Drivers are provided guidance on the appropriate response to
the clearance interval in each state through yellow light laws that
can be classified into three types:
Class 1 - vehicles can enter the intersection at any point during
the yellow change interval and if entered during yellow, it is
legal to be in the intersection during the red,
Class 2 - vehicles cannot enter or be in the intersection on red, and

Class 3 - vehicles should stop during the yellow indication, but
they may proceed with caution through the intersection if it is
not possible to do safely.16
Prior work has termed Class 1 to be a permissive yellow law and
Class 2 and 3 to be restrictive yellow laws.
The primary advantage of permissive yellow laws is to maximize
the number of drivers who lawfully respond to the CY. The disadvantage of the permissive yellow law is that it can create a situation
where the cross-street driver receives a CG but must yield the rightof-way (ROW) to a crossing vehicle on the alternate approach before
entering the intersection, which can be of particular concern for a
driver entering an intersection at the end of the yellow indication
at a wide intersection without an all-read phase. Parsonson et al.
(1993) indicate that about 60 percent of drivers do not understand
that they should yield the ROW to crossing vehicles when they
receive a CG. One solution recommended by Parsonson was to
provide an all-red interval following the CY permitting vehicles
to cross the intersection before conflicting traffic movements
received a CG.17
Currently there are four states that follow the Class 2 restrictive
yellow law and nine states that follow the Class 3 restrictive
yellow law. The remaining 37 states follow the permissive yellow
law (Class 1). Figure 1 displays yellow law classifications for each
state as defined by NCHRP Report 731. A self-published report by

Figure 1. Classification of yellow light laws by state (NCHRP 731).
w w w .i t e.or g

Ja nu ar y 2018

45


http://www.ite.org

Table of Contents for the Digital Edition of ITE Journal January 2018

President’s Message
Director’s Message
Introducing the 2018 ITE International Board of Direction
Introducing the 2018 LeadershipITE Class
Your ITE Councils: An Overview of the ITE Councils in 2018
People in the Profession
ITE News
Member to Member: Congratulations to ITE’s Three New Honorary Members
Where in the World?
Calendar
Industry News
New Products
ITE Adopts 2018–2020 Strategic Plan
Finding the Courage to Lead the Way
Providing Vehicular Cyclists with Routine Accommodation in the United States as Part of Complete Streets
Variable Driver Responses to Yellow Indications: An Operational Challenge and Safety Concern
Professional Services Directory
ITE Journal January 2018 - 1
ITE Journal January 2018 - 2
ITE Journal January 2018 - 3
ITE Journal January 2018 - President’s Message
ITE Journal January 2018 - 5
ITE Journal January 2018 - Director’s Message
ITE Journal January 2018 - 7
ITE Journal January 2018 - Introducing the 2018 ITE International Board of Direction
ITE Journal January 2018 - 9
ITE Journal January 2018 - 10
ITE Journal January 2018 - 11
ITE Journal January 2018 - Introducing the 2018 LeadershipITE Class
ITE Journal January 2018 - 13
ITE Journal January 2018 - 14
ITE Journal January 2018 - 15
ITE Journal January 2018 - 16
ITE Journal January 2018 - 17
ITE Journal January 2018 - Your ITE Councils: An Overview of the ITE Councils in 2018
ITE Journal January 2018 - 19
ITE Journal January 2018 - People in the Profession
ITE Journal January 2018 - ITE News
ITE Journal January 2018 - Member to Member: Congratulations to ITE’s Three New Honorary Members
ITE Journal January 2018 - 23
ITE Journal January 2018 - 24
ITE Journal January 2018 - 25
ITE Journal January 2018 - 26
ITE Journal January 2018 - 27
ITE Journal January 2018 - Calendar
ITE Journal January 2018 - New Products
ITE Journal January 2018 - 30
ITE Journal January 2018 - 31
ITE Journal January 2018 - ITE Adopts 2018–2020 Strategic Plan
ITE Journal January 2018 - 33
ITE Journal January 2018 - 34
ITE Journal January 2018 - Finding the Courage to Lead the Way
ITE Journal January 2018 - 36
ITE Journal January 2018 - 37
ITE Journal January 2018 - Providing Vehicular Cyclists with Routine Accommodation in the United States as Part of Complete Streets
ITE Journal January 2018 - 39
ITE Journal January 2018 - 40
ITE Journal January 2018 - 41
ITE Journal January 2018 - 42
ITE Journal January 2018 - 43
ITE Journal January 2018 - Variable Driver Responses to Yellow Indications: An Operational Challenge and Safety Concern
ITE Journal January 2018 - 45
ITE Journal January 2018 - 46
ITE Journal January 2018 - 47
ITE Journal January 2018 - 48
ITE Journal January 2018 - 49
ITE Journal January 2018 - Professional Services Directory
ITE Journal January 2018 - 51
ITE Journal January 2018 - 52
ITE Journal January 2018 - Outsert1
ITE Journal January 2018 - Outsert2
ITE Journal January 2018 - Outsert3
ITE Journal January 2018 - Outsert4
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