CE 436 Traffic Engineering

Topic 3: Roadways (Ch. 3.1)

& Control (Ch. 4.1)

Prof. Saad AlGadhi

CE 436 –Traffic Engineering

King Saud University

email: salgadhi@ksu.edu.sa

Highway & Trip Functions(Ch. 3.1)

2 Highway Functions:

Accessibility

Mobility

6 Trip Functions:

Main Movement

Transition

Distribution

Collection

Access

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Highway Classification

4 Highway Classes:

Limited-access facilities (Freeways)

Arterials

Collectors

Local streets

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Figure 3.1 Hierarchy of Roadway Classifications

Table 3.1: Through Service Provided by Various Roadway Categories

Figure 3.2 Suburban Residential Subdivision Illustrated

Traffic Control Devices(Ch. 4.1)

3 broad categories Traffic markings

Traffic signs

Traffic Signals

A principal objective of the Manual of Uniform Traffic Control Devices (MUTCD) is to establish uniformity in traffic control devices’:

Use

Placemen, and

Design

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Purpose of Traffic Control Devices

Traffic Control Devices purpose is "to promote highway safety and efficiency by providing for orderly movement of all road users on streets and highways, bikeways, public facilities, and private property open to public travel throughout the Nation.

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Requirement for a Traffic Control Device

Five requirements for a traffic control device to be effective in fulfilling its mission.

A traffic control device must:

1. Fulfill a need

2. Command attention

3. Convey a clear, simple message

4. Command respect of road users

5. Give adequate time for a proper response

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MUTCD Contents

The MUTCD addresses three critical aspects of traffic control devices. It contains:

1. Detailed standards for the physical design of the device, specifying shape, size, colors, legend types and sizes, and specific legend.

2. Detailed standards and guidelines on where devices should be located with respect to the traveled way.

3. Warrants, or conditions, that justify the use of a particular device.

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Communicating with the Driver

The driver is accustomed to receiving a certain message in a clear and standard fashion, often with redundancy

A number of mechanisms are used to convey messages, which make use of recognized human limitations, particularly with respect to eyesight:

Color

Shape

Pattern

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Required Reading

Ch. 3: Roadways & Their Geometrics

Section 3.1

Ch. 4: Introd. to Traffic Control Devices

Section 4.1

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