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
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
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
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