Introduction to Traffic Engineering

Objectives of course Help students lay solid foundation

of traffic engineering as a whole Help students get general

knowledge of traffic engineering from both theory and practice

Lead students to traffic/transportation professional world

Some Basic Statistics,

Over 158.5 million US drivers drove over 1.86 trillion vehicle-miles in over 172 million regulated vehicles

47,000 people were killed in highway accidents, with a rate of 2.57 deaths/100 million vehicle-miles of travel

State and local highway user taxes generated over $40.6 billion

Pakistan Every year more than 0.5 million people are killed

(about one life in every minute) & more than 10-million people injured in road accidents.

PAKISTAN is on the 7-th position in fatal accidents for every 10,000 vehicles.

Road accidents can not be totally prevented but by suitable traffic engineering measures the accident rates can be decreased.

The role of traffic engineer is to carry out systematic accident studies to investigate the causes of accidents and to suggest the remedial measures.

Bar chart shows the position of PAKISTAN.

3. 2

3. 8

4. 2

2. 124

0

0. 5

1

1. 5

2

2. 5

3

3. 5

4

4. 5

1987 1991 1995 1999 2003 2007 2010

1系列

2系列

3系列

trend 1

trend 2

trend 3

mi l l i on

Trend forecast for auto development in Beijing

Crisis in Serving the Growing Urban Traffic Demand

Traffic demand is growingadditional ROW is limited due to financial, space, and social reasons Current use of ROW do not allow capacity improvements of the magnitude needed to meet the future demand

Urban Traffic Demand

3. 2

3. 8

4. 2

2. 124

0

0. 5

1

1. 5

2

2. 5

3

3. 5

4

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1987 1991 1995 1999 2003 2007 2010

1系列

2系列

3系列

trend 1

trend 2

trend 3

mi l l i on

Trend forecast for auto development in Beijing

Traffic Problems

Grid lock – capacity problem Pot holes – road

maintenance problem Construction barrels –

foreign object on road Poor drivers – driver

behavior

Traffic Problems

Roadway drainage – drainage system problem

Gawkers – inattentive drivers Roadway geometry problem –

deficiency in geometric design Environmental problem

Traffic Crash Problem

Traffic crashes Fatalities – persons killed Injuries – having injuries of various

severities Property damages – only a damage to

the vehicle without injury

Challenges Traffic Engineers Face

Change in notion from increasing capacity to meet demand to managing the movement of vehicle and people

Ever-increasing congestion Safety and security of transportation

facilities Technologically sound solutions may not be

socially acceptable (staggering of work time; public transit)

Congestion on Roadway of Beijing

Evacuation before hurricane in Houston, USA, 2005

9.11 event in 2001, USA

Traffic paralysis due to snow storm in southern China 2008

1. Definition, scope and goal Definition of Traffic Engineering --- It is the phase of transportation

engineering that deals with the planning, geometric design and traffic operations of roads, streets and highways, their networks, terminals, abutting lands, and relationships with other modes of transportation

Traffic Engineeringdefined as that phase of engineering which deals with the safe and efficient movement of people and goods on streets and highways.

Transportation mode includes: land, rail, water,air and pipe (refer to Table 1.1 on page 8-9)

The focus of this course is on surface (land) transportation and connection with other modes

Scope of Traffic Engineering --- surface (land ) transportation; relationships and connection with other modes of transportation

Major modes of surface transportation --- automobile, bus, truck and bike

Goal of Traffic Engineering --- explore how to provide for the safe, rapid, comfortable, convenient, economical, and environmentally compatible movement of people and goods.

Safe --- public safety Rapid --- time value and customer service Comfortable/convenient --- level of service Economical --- social cost Environmental --- clean air and sustainability Movement = mobility

Main Elements in Traffic Engineering

Traffic studies --- data collection and reduction

Performance evaluation --- set of criteria to measure the quality of traffic performance

Facility design --- functional and geometric designs

Traffic control --- establishment of traffic regulation and their communication to the driver through signs, markings, and signals

Traffic operations --- traffic organization, transit operation,

TSM --- Transportation Systems Management

ITS --- Intelligent Transportation Systems

8. References ITE --- Institute of Transportation Engineers TRB --- Transportation Research Board ASCE --- American Society of Civil Engineers MUTCD --- Manual on Uniform Traffic Control Devices HCM 2000--- Highway Capacity Manual AASHTO Green Book --- American Association of

State Highway and Transportation Officials named a book titled “A Police on the Geometric Design of Highway and Street”

The Traffic Engineering Handbook Trip Generation Handbook 2000 Access Management Manual 2003

Traffic Control Devices

Traffic Control Devices

Overview

Traffic control device is the medium used for communicating between traffic engineer and road users.

Unlike other modes of transportation, there is no control on the drivers using the road.

Here traffic control devices comes to the help of the traffic engineer.

Traffic Control Devices

Communication of traffic laws and regulations to drivers by means of control devices:

Signs Signals Markings

Standards and Guidelines

Manual of Uniform Traffic Control Devices (MUTCD) • Federal MUTCD• State MUTCD

Requirements of a Traffic Control Device

Fulfill a need Command attention Convey a clear, simple meaning Command respect of road users Give adequate time for proper response

Considerations to insure the

requirements

Design Placement Operation Maintenance Uniformity

Using the Manual

Manual provides the standards and guidelines, but it is not a substitute for engineering decision

Definitions need careful attention: Shall – mandatory condition Should – advisory condition May – permissive condition

General Color Coding

Yellow – general warning Red – stop or prohibition Blue – motorist services guidance and evacuation route Green – Direction guidance Brown – recreational and cultural interest guidance Orange – construction and maintenance warning Black – regulation White – regulation

Signs

Three major categories: Regulatory – give notice of traffic laws or regulations Warning – call attention to conditions that are potentially hazardous

Guide – show route designations, destinations, directions, distances, services, and such information

Regulatory Signs notice of traffic law and regulations

Right-of-way – STOP, YIELD Speed Control Movement Control Parking Pedestrian Miscellaneous

Warning Signsdirect attention to condition on highway of potential

hazards

Changes in horizontal alignment Intersections Advance warning of control devices Converging traffic lanes Narrow roadways Changes in highway design Grades Roadway surface conditions Railroad crossings Miscellaneous others

Guide Signsindicate rout designation, direction, distances and

other geographic information.

Route marker assemblies Directional information signs Services information signs Cultural information signs

Construction and Maintenance Signs

Warning signs in black on an orange background

Directional signs and street names in conjunction with a detour in black on an orange background

Changeable Message Signs

Designed to display variable messages Accident Congestion Detour Enforcement and Public Safety Information Approx. time to reach a destination Other temporary warnings

Sign Illumination

Retroreflection

Shape of Signs

Sign Colors

Regulatory Sign

STOP Sign

Not less than1.8 m(6 ft)

Not

less

th

an1.

5 m

(5 ft

)

Location of STOP and YIELD Sign

Location of STOP Sign

Typical One Way Signing for Divided Highways

Median < 30 ft.

Speed Limit Sign

Not

less

th

an2.

1 m

(7 ft

)

Not less than0.6 m

(2 ft)

Warning Signs

Warning Signs

Curve Warning Sign

Not less than1.8 m(6 ft)

Not

less

th

an1.

5 m

(5 ft

)

Warning With Advisory Speed

Not less than1.8 m(6 ft)

Not

less

th

an1.

2 m

(4 ft

)

Island Warning Sign

Not

less

th

an2.

1 m

(7 ft

) N

ot le

ss

than

1.2

m(4

ft)

Application of Warning Signs

Application of Warning Signs

Application of Warning Signs

Guide Signs

Guide Signs

Guide Signs

Not less than1.8 m(6 ft) N

ot

less

th

an 1.5 m

(5 ft

)

END