Highway Engineering

Planning, Design, and Operations

Daniel J. Findley, Bastian Schroeder, Christopher M. Cunningham, Thomas H. Brown Jr

• Publisher: Butterworth-Heinemann
• Year: 2015
• ISBN:
  9780128013557
• Topic: Tecnología e ingeniería
• Subtopic: Construcción e ingeniería arquitectónica

This book helps readers maximize effectiveness in all facets of highway engineering including planning, design, operations, safety, and geotechnical engineering. Highway Engineering: Planning, Design, and Operations features a seven part treatment, beginning with a clear and rigorous exposition of highway engineering concepts. These include project development, and the relationship between planning, operations, safety, and highway types (functional classification). Planning concepts and a four-step process overview are covered, along with trip generation, equations versus rates, trip distribution, and shortest path models equations versus rates. This is followed by parts concerning applications for horizontal and vertical alignment, highway geometric design, traffic operations, traffic safety, and civil engineering topics.

• Covers traffic flow relationships and traffic impact analysis, collision analysis, road safety audits, advisory speeds
• Applications for horizontal and vertical alignment, highway geometric design, traffic operations, traffic safety, civil engineering topics
• Engineering considerations for highway planning design and construction are included, such as hydraulics, geotechnical engineering, and structural engineering

Part 1

Introduction

Daniel J. Findley, PhD, PE, Institute for Transportation Research and Education, North Carolina State University

Abstract

This part provides a summary of the topics covered in this book.

Keywords

Highway; Roadways; Roads; Streets; Planning; Operations; Design; Safety; Structures; Geotechnical; Hydraulics; Freeway; Intersection; Interchange

Contents

1.1 Introduction 2

1.2 Organization of the Book 4

1.2.1 Part 2: Transportation Planning 4

1.2.2 Part 3: Horizontal and Vertical Alignment 5

1.2.3 Part 4: Highway Geometric Design 5

1.2.4 Part 5: Traffic Operations 6

1.2.5 Part 6: Traffic Safety 6

1.2.6 Part 7: Geotechnical 6

1.2.7 Part 8: Structures 7

1.2.8 Part 9: Hydraulics 7

1.3 Functional Classifications of Highway 7

1.3.1 Arterials 8

1.3.2 Collectors 10

1.3.3 Local Streets 10

1.4 Types of Intersections 12

1.4.1 Unsignalized Intersections 13

1.4.2 Signalized Intersections 15

1.4.3 Alternative Intersections 15

1.1 Introduction

Highway engineering is a subset of transportation engineering, which itself is typically a component of civil engineering. The presence of more than 4 million miles of public roads in the United States (BTS, 2014) serving widely varying traffic volumes and trip purposes, emphasizes the need for qualified and capable professionals to address problems and improve the system. Two primary metrics of quality of highways are efficiency (measured by delay, travel time, speed, or other operational characteristics) and safety (measured by collisions or fatalities). An inefficient highway can have detrimental effects on local and regional economies and drivers, by burdening the movement of goods and people with additional costs and loss of productivity. The continual improvement of highways is also essential to reduce deaths resulting from collisions on roadways, which, in the United States, totaled 33,561 fatalities in 2012 (NHTSA, 2014).

All users and modes on the transportation system play important roles in the efficient and effective movement of goods and people. This book focuses on highway infrastructure and the operations of that system, and documents the methodologies and analysis practices for the design, operational analysis, and safety assessment of the system. A fundamental consideration in highway engineering is the human element. There is a need for meeting drivers’ expectations or effectively communicating any disruptions to their expectations. This is illustrated throughout highway engineering, as violations to a driver’s expectation without proper notification results in operational inefficiency or safety concerns.

Highway engineering is a multidisciplinary field with interconnected subdisciplines that include planning, safety, operations, design, and related fields such as structural, hydraulic, and geotechnical engineering. This book presents thematic topics within highway engineering and the holistic system required to develop a highway from initial planning through the full design process and operations. Ultimately, to meet overall efficiency and effectiveness goals, highway engineers must understand how their role fits into the larger process, and apply flexibility with the implementation of standard practice to maximize the overall final product. Decisions made throughout the design process must consider impacts on safety and operations. For instance, in the alignment of a highway, an engineer should attempt tangential and perpendicular crossings of water features or overpasses to minimize the complexity and cost of structural elements. Similarly, operational treatments may affect design decisions. Figure 1.1 shows a roadway setup with reversible lanes, allowing for peak direction traffic to have additional lanes during peak travel times. Reversible lanes are particularly useful in areas with very unbalanced traffic flows, such as during entertainment or sporting events or into and out of a central business district. This simple example illustrates how the design and operations of a roadway are closely interrelated and how clearly communicating those principles to the driver—the human element—is critical to assure safe operations.

Figure 1.1 Reversible lanes.

There are several questions that might be asked about the topic of highway engineering, and these are addressed in the following parts of this book.

• How do we know when we need to build a new highway or make improvements to an existing highway?

• How do we know that a highway is functioning as designed (from an efficiency and safety perspective)?

• What geometric components are necessary to produce an efficient and safe highway?

• How does an individual highway engineer’s role fit into the overall completion of a highway project?

• What other engineering is needed in a highway project?

• What aspects related to those areas should highway engineers consider in their efforts?

References

1. National Highway Traffic Safety Administration (NHTSA), 2014. Fatality Analysis Reporting System (FARS) Encyclopedia. National Highway Traffic Safety Administration.

2. Bureau of Transportation Statistics (BTS), 2014. Table 1-1: System mileage within the United States. Bureau of Transportation Statistics. Office of the Assistant Secretary for Research and Technology. United States Department of Transportation.

1.2 Organization of the Book

This book is organized into nine parts, each addressing one aspect of the field of highway engineering. Each part presents a standalone overview of a component of highway engineering, details analysis methodologies, defines key concepts, and presents applications and examples. However, all nine parts interrelate; for example, design decisions can impact safety, or the forecast of traffic demands through transportation planning is closely tied to the expected operations of an intersection or facility. These correlations and interactions will be discussed throughout each part.

1.2.1 Part 2: Transportation Planning

Highway engineers need to be able to recognize when a highway has reached its service life and which improvements and modifications should be made to that facility, or if a new facility is needed. Part 2 describes the long-term planning and forecasting process and presents the methodologies used to predict when and where transportation improvements are needed. Many planning applications are closely tied to new developments on a local or regional scale that are expected to impact traffic patterns. The planning methods are used to predict how many trips a new development generates, where those drivers are expected to go, what facilities or routes they are expected to take, and even what mode of transportation they are likely to choose. This part of the book presents and discusses the use of planning tools in the four key steps of trip generation, trip distribution, traffic assignment, and modal split, and advises the engineer on making informed decisions.

1.2.2 Part 3: Horizontal and Vertical Alignment

Part 3 describes the decisions related to choosing an optimal highway alignment given substantial environmental and design considerations, including: corridor selection, traverses, sight distance, horizontal alignment, and vertical alignment. Corridor selection follows transportation planning, which identifies the broader transportation needs of a community. Corridor selection is comprised of the broad task of choosing a highway location through decisions relating to minimizing costs and impacts to the human and natural environment. The engineering computations of such corridors are derived from consideration of th...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• Part 1. Introduction
• Part 2. Transportation Planning
• Part 3. Horizontal and Vertical Alignment
• Part 4. Highway Geometric Design
• Part 5. Traffic Operations
• Part 6. Traffic Safety
• Part 7. Geotechnical
• Part 8. Structures
• Part 9. Hydraulics
• Index