Traffic Engineering: Definition, Meaning, Components (Sub-systems) & PIEV – Time

Traffic engineering: roadway traffic | Makati intercession | src: wikipedia

Traffic
engineering can be defined as the application of engineering principles to
manage the movement of vehicles. Traffic engineering has been concerned
traditionally with that phase of engineering that deals with the planning,
control and traffic operation of roadway networks and their relationship with
other modes of transportation including the planning and provision of public
transportation and pedestrian modes.

In
a nutshell, traffic engineering can be defined as the art and science of
estimating traffic demand and highway capacity, and measuring as well as determining
the relationship among traffic variables and the application of this knowledge
to planning, designing, operating and administering highway facilities in order
to achieve an efficient movement of persons and goods.

The
following are the needs for traffic engineering:

1.     To promote safety

2.     To promote economy and
efficiency: The traffic engineer ensures maximum utilization of available
resources by scientific management of traffic and also to recommend when and
where these facilities are necessary.

The
sub-systems or components of traffic system are:

1.     The road users viz., drivers
and pedestrians

2.     The roadway

3.     The vehicle

It
is pertinent to note that road users are the greatest problem in traffic
system. This calls for measures to enhance efficient functionality in the road
systems. This will provide for free flow of traffic within the traffic system. In
order to do this, road signs are provided to influence users’ reactions to
external stimuli. There is hence, a reaction process used in the design of
traffic signal known as PIEV – time.

What
is PIEV – time?

PIEV
as an acronym with the following meanings:

P means Perception: This is the time required for the driver or road user
to see or perceive the stimulus or stimuli as the case may be.

I means Identification: This is the time required for the driver or road
user to identify the stimulus. This happens within the brain

E means Emotion: This refers to the will of the road user to taking an
action or decision regarding the stimulus or stimuli, and what proper action to
take. Here, the road user makes decision on what to do regarding the stimulus.

V means Volition: This refers to the actual action taken by the road user
with regards to the external stimulus.

PIEV – time therefore, is the total
time required to perceive and complete a reaction to a stimulus, and is equal
to the sum of the necessary times for perception, identification, emotion and
volition.