# GEOMETRIC DESIGN OF HIGHWAY

CHAT ON WHATSAPP (+234) 0803-766-4978

GEOMETRIC DESIGN OF HIGHWAY

ABSTRACT

Geometric design of highways is an important factor to be considered before highway construction as it necessitates the determination of specific design elements, which include: the number of lanes, lane width, median and width, length of acceleration and deceleration lanes for on and off ramps, need for truck climbing lanes for steep grades, curve radii required for vehicle turning and the alignment required to provide adequate stopping and passing sight distances.  This project work focuses mainly on highway horizontal and vertical alignments which are the most important components of geometric design and intersection. These project works also discusses geometric design of cross section,, sight distance, procedures for highway alignment and the comprehensive plan and profile detailing using manual and automated then comparing the result.

TABLE OF CONTENT

PAGES

Title page…………………………………………………………………………...

Certification………………………………………………………………………...........i

Dedication……………………………………………………………………………......ii

Acknowledgement……………………………………………………………….............iii

Abstract………………………………………………………………………..…............iv

List of Tables……………………………………………………………………………...viii

List of Figures……………………………………………………………………………..ix

CHAPTER ONE: INTRODUCTION

1.1    Historical Background of Road ……………………………………………………....1

1.2    The Purpose of Highway ………………………………………………………..……2

1.3    Geometric Design  ………………………………………………………………..…..3

1.4    Classification of Roads …………………………………………………………….....4

1.5    Background and purpose ……………………………………………………………..5

1.6    Aim and Objectives of the study …………………………………………..................6

1.7    Scope of Study ………………………………………..................................................6

1.8    Outline of Study ………………………………………………………………………6

CHAPTER TWO: LITERATURE REVIEW

2.0.1 Past Research Work on Highway Geometric DESIGN ……………....................7

2.1    Design Element………………………………………………………………………...17

2.1.1  Design Speed …………………………………………………………………...18

2.1.2   Design Vehicle …………………………………………………………………21

2.1.3   Sight Distance ………………………………………………………………….22

2.1.4   Horizontal Alignment…………………………………………………………...32

2.1.5   Vertical Alignment……………………………………………………………...33

2.1.6    Capacity………………………………………………………………………..34

2.2    Road Survey  ………………………………………………………………………...…35

2.2.1   Reconnaissance Survey………………………………………………………….35

2.2.2   Preliminary Location Survey……………………………………………………35

2.2.3    Final Location Survey…………………………………………………………..36

2.3    Total Station ……………………………………………………………………………36

2.3.1   Advantages of total station ……………………………………………………..37

2.3.2   Disadvantages of total station …………………………………………………..37

2.4    Computer Aided Design ………………………………………………………………..38

2.4.1   AutoCad Civil 3D ……………………………………………………………….38

2.4.2   Advantages of CAD over manual Drawing ……………………………………..39

2.4.3   Highway Engineering Software………………………….....................................39

2.5    Safety…………………………………………………………………………………....40

CHAPTER THREE: METHODOLOGY

3.1    Description of the case-study road ……………………………………………………...42

3.2    Alignment ……………………………………………………………………………….44

3.3    Vertical curves ………………………………………………………………………..…47

3.3.1   Sag vertical curve ……………………………………………………………….47

3.3.2   Crest vertical curve ……………………………………………………………..48

3.4    Horizontal curve …………………………………………………………………………49

3.5    Typical example on the calculation of horizontal curve ………………………………...51

CHAPTER FOUR: RESULT AND DATA ANALYSIS

4.1      Horizontal Curves………………………………………………………………………54

4.2 Vertical Curves………………………………………………………………...………55

4.3       Comparison of horizontal curves results……………………………………………….68

4.4 Comparisons of vertical curves results………………………………………………...69  4.5 Discussion of results.......................................................................................................72

CHAPTER FIVE: SUMMARY AND CONCLUSION

5.1 Summary……………………………………………………………………………….73

5.2 Conclusion……………………………………………………………………………..74

References……………………………………………………………………………..75

LIST OF TABLES

Table 2.1 Passing sight distance                                                                                          11

Table 2.2 Minimum sight distance used on highway design                                               25

Table 2.3 Sight distance-rural roads (British practice)                                                        29

Table 2.4 Sight distance-urban roads (British practice)                                                      29

Table 2.5 Advantages of Automated drawing over Manual drawing                                 38

Table 4.1 Horizontal curves computation results                                                                58

Table 4.2 Vertical curves computation results (Sample)                                                     59

Table 4.3 Comparison of horizontal curves results                                                             60

Table 4.4 Comparison of vertical curves parameter results                                                60

LIST OF FIGURES

Figure 2.1 Presentation of horizontal curve images for comparison                        12

Figure 2.2 Sight distance for vehicle turning left from major road                           26

Figure 2.3 Decision sight distance model                                                                 28

Figure 2.4 Minimum stopping sight distance (Crest curve)                                     29

Figure 2.5 Minimum stopping sight distance (Sag curve)                                        30

Figure 2.6 Passing sight distance                                                                               31

Figure 3.1 Google map showing the location of the case study area                        48

Figure 3.2 Vertical curve terminology (Profile view shown)                                   52

Figure 3.3 Geometry of the circle                                                                             53

Figure 3.4 Relationship between the degree of curve (D) and the circle                  54

Figure 4.1 Graph showing the difference in the K (Rate of vertical                         62

curvature) value of manual and automated

Figure 4.2 Graph showing the difference in the LC (length of Chord)                     63

value of manual and automated

Figure 4.3: Graph showing the difference in the TL (Tangent   63

length) value of manual and automated

Figure 4.4: Graph showing the difference in the finished level value                       64

of manual, automated and existing level

CHAPTER ONE

1. INTRODUCTIONSince the attainment of independence, Nigeria has witnessed rapid economic and social development, which has open up the need for travelling between cities which led to increase in the need for good and safe road.Highway is any public road or other public way on land; the term exists in distinction to waterway also can said to be high-speed roads designed to connect major cities. A highway is a major road for any form of motor transport which vehicles and the public in general may lawfully pass without license. A road on the other hand is a way for vehicle and other types of traffic (human or animal) which may or may not be lawfully usable to the public at large. Highways are vitally important to a country’s economic development. The construction of a high quality road network directly increases a nation’s economic output by reducing journey times and costs, making a region more attractive economically. The actual construction process will have the added effect of stimulating the construction market. Roads could be considered as a cause and the consequence of civilization, as they both precede and follow it.

1.1 HISTORICAL BACKGROUND OF ROAD

The need for road construction came up with the invention of the wheel some 5000 years ago. Prior to this invention, people and transportation beast simply moved on tracks which were only wide enough for their comfort. With the invention of the wheel, there was the need for improvement on the existing tacks to provide firmer and wider surfaces with better riding qualities to accommodate higher volume of traffic. These improvements were carried out in order to increase the safety and speed of conveying people and goods from one place to another for social and commercial purposes.

Road transport is one of the most common mode of transport. Roads in the form of track ways, human pathways etc. were used even from the pre-historic times. Since then many experiments were going on to make the riding safe and comfort. Thus road construction became an inseparable part of many civilizations and empires.  The need for road construction came up with the invention of the wheel some decades ago. Prior to this invention, people and transportation beast simply moved on tracks which were only wide enough for their comfort. With the invention of the wheel, there was the need for improvement on the existing tacks to provide firmer and wider surfaces with better riding qualities to accommodate higher volume of traffic. These improvements were carried out in order to increase the safety and speed of conveying people and goods from one place to another for social and commercial purposes.

There are many different types of highways. Highways differ primarily in the amount of access control they have and, therefore, in the amount of traffic they are designed to carry. Highway with fully controlled access can handle the most traffic and are built to the highest construction standards. Inter-state highways. Vehicles that enter or exit these types of highway can do so only at certain points along the highway, generally by using special entrance and exit ramps. The ramps allow vehicle to access the road without disturbing the flow of traffic. Incoming vehicles must merge with flowing traffic, and vehicles leaving the highway use exit ramps that guide them off the highway without blocking the traffic behind. Intersections with other roads are avoided by using either bridge known as overpasses to carry one roadway under another. Finished strips called shoulders on the edges of highways allow drivers of disabled vehicles to make repairs or await assistance without blocking traffic.

1. THE PURPOSE OF  HIGHWAYThe purpose of the highway is to provide a means of reducing the stress or pressure due to a wheel load to the minimum value which the ground under the structure can support. This is why materials of the highest strength are used for the surface. Other purposes of highway are listed below:

⦁ It provide a skid resistance surface

⦁ It provide wider riding surface to accommodate anticipated traffic volume

⦁ It provide a firmer riding surface ands

⦁ It provide a smooth riding surface

⦁ It provide efficient and convenient movement of people and goods from one place to another.The intensity of the stress is greatest at the surface of the road and it is distributed in a pyramid from down the depth of the formation. As long as the stress reaching the sub grade does not exceed the resistance put forth by the sub grade, there will be no distortion or damage to the road surface.

1.3 GEOMETRIC DESIGN

Geometric design is defined as the design or proportioning of the visible elements of the street or highway. The geometry of the roadway is of central importance since it provides the framework for the design of other highway elements. In addition, the geometric design establishes the basic nature and quality of the vehicle path, which has a primary effect upon the overall safety characteristics of the street or highway.

The design of roadway geometry must be conducted in close coordination with other design elements. These other elements include: pavement design, roadway lighting, traffic control devices, transit, drainage, and structural design. The design should consider safe roadside clear zones, bicycle and pedestrian safety accommodation, emergency response, and maintenance capabilities.

The geometric design of highways deals with the dimensions and layout of visible features like of the highway. The emphasis of the geometric design is to address the requirement of the driver and the vehicle such as safety, comfort, efficiency, etc. The features normally considered are the cross section elements, sight distance consideration, horizontal curvature, gradients, and intersection. The design of these features is to a great extend influenced by driver behavior and psychology, vehicle characteristics, traffic characteristics such as speed and volume. Proper geometric design will help in the reduction of accidents and their severity. Therefore, the objective of geometric design is to provide optimum efficiency in traffic operation and maximum safety at reasonable cost. The planning cannot be done stage wise like that of a pavement, but has to be done well in advance. The main components that will be discussed are:

⦁ Design speed

⦁ Design vehicle

⦁ Safety

⦁ Sight distance

⦁ Alignment

⦁ CapacityThe safety characteristics of the design should be given primary consideration. The initial establishment of sufficient right of way and adequate horizontal and vertical alignment is not only essential from a safety standpoint, but also necessary to allow future upgrading and expansion without exorbitant expenditure of highway funds.

1.4 CLASSIFICATION OF ROADS

Roads can be classified in many ways. The classification based on speed and accessibility is the most generic one. Note: As the accessibility of road increases, the speed reduces. Accordingly, the roads can classify as follows in the order of increased accessibility and reduced speeds.

⦁ Freeways

⦁ Expressways

⦁ Highways

⦁ Arterials

⦁ Local streets

⦁ Collector’s streets

⦁ Freeways: Freeways are access controlled divided highways. Most freeways are four lanes, two lanes each direction, but many freeways widen to incorporate more lanes as they enter urban areas. Access is controlled through the use of interchanges, and the type of interchange depends upon the kind of intersecting road way (rural roads, another freeway etc.)

⦁ Expressways: They are superior type of highways and are designed for high speeds (120 km/hr. is common), high traffic volume and safety. They are generally provided with grade separations at intersections. Parking, loading and unloading of goods and pedestrian traffic is not allowed on expressways.

⦁ Highways: They represent the superior type of roads in the country. Highways are of two types – rural highways and urban highways. Rural highways are those passing through rural areas (villages) and urban highways are those passing through large cities and towns, i.e. Urban areas.

⦁ Arterials: It is a general term denoting a street primarily meant for through traffic usually on a continuous route. They are generally divided highways with fully or partially controlled access. Parking, loading and unloading activities are usually restricted and regulated. Pedestrians are allowed to cross only at intersections/designated pedestrian crossings.

⦁ Local streets: A local street is the one which is primarily intended for access to residence, business or abutting property. It does not normally carry large volume of traffic and also it allows unrestricted parking and pedestrian movements.

⦁ Collector’s streets: These are streets intended for collecting and distributing traffic to and from local streets and also for providing access to arterial streets. Normally full access is provided on these streets. There are few parking restrictions except during peak hours.

1.5BACKGROUND AND PURPOSE

Highway geometry should be designed for vehicle traffic safety and efficiency, particularly on the trunk roads or Expressways on which traffic function must be most important. Though the design policy was established, the prerequisites of design have been imaginary or extremely limited. For example, minimum radius of horizontal curve is defined with design speed, super elevation and side slip friction factor. The actual operating speed must correspond to something speed, but it did not work well to be used for design purpose of road geometry, or did not calibrated enough because of the difficulty of data acquisition. Such an estimation model should have a feature including driver’s perception and behavior.

1.6   AIM AND OBJECTIVES OF THE STUDY

The aim of the study is to perform the geometric design of a selected case study road.

And comparison between Manual and Automated design.

The objectives required to achieve the above aim include:

⦁ Design of all vertical alignment components

⦁ Design of all horizontal alignment components

⦁ Comprehensive plan and profile detailing of the case study road.1.7    SCOPE OF STUDY

The scope of this study covers the geometric design of highway at Anka road, bukkuyum L.G.A Zamfara State. Using manual design and comparing with automated design.

1.8 OUTLINE OF STUDY

For a proper understanding of this project report it has been divided into five chapters.

Chapter one introduced the project; chapter two discusses the relevant literature in respect to this project. Chapter three contains the design methods of highway designed detail. Chapter four contains the result and analysis and finally recommendations and conclusion based on findings is shown in chapter five.

.

## GEOMETRIC DESIGN OF HIGHWAY

OR CHAT ON WHATSAPP (+234) 0803-766-4978

TYPE IN YOUR TOPIC AND CLICK SEARCH.

###### RESEARCHWAP.ORG
Researchwap.org is an online repository for free project topics and research materials, articles and custom writing of research works. We’re an online resource centre that provides a vast database for students to access numerous research project topics and materials. Researchwap.org guides and assist Postgraduate, Undergraduate and Final Year Students with well researched and quality project topics, topic ideas, research guides and project materials. We’re reliable and trustworthy, and we really understand what is called “time factor”, that is why we’ve simplified the process so that students can get their research projects ready on time. Our platform provides more educational services, such as hiring a writer, research analysis, and software for computer science research and we also seriously adhere to a timely delivery.

### TESTIMONIES FROM OUR CLIENTS

Please feel free to carefully review some written and captured responses from our satisfied clients.

• "Exceptionally outstanding. Highly recommend for all who wish to have effective and excellent project defence. Easily Accessable, Affordable, Effective and effective."

Debby Henry George, Massachusetts Institute of Technology (MIT), Cambridge, USA.
• "I saw this website on facebook page and I did not even bother since I was in a hurry to complete my project. But I am totally amazed that when I visited the website and saw the topic I was looking for and I decided to give a try and now I have received it within an hour after ordering the material. Am grateful guys!"

Hilary Yusuf, United States International University Africa, Nairobi, Kenya.
• "Researchwap.org is a website I recommend to all student and researchers within and outside the country. The web owners are doing great job and I appreciate them for that. Once again, thank you very much "researchwap.org" and God bless you and your business! ."

Debby Henry George, Massachusetts Institute of Technology (MIT), Cambridge, USA.
• "Great User Experience, Nice flows and Superb functionalities.The app is indeed a great tech innovation for greasing the wheels of final year, research and other pedagogical related project works. A trial would definitely convince you."

Lamilare Valentine, Kwame Nkrumah University, Kumasi, Ghana.
• "I love what you guys are doing, your material guided me well through my research. Thank you for helping me achieve academic success."

Sampson, University of Nigeria, Nsukka.
• "researchwap.com is God-sent! I got good grades in my seminar and project with the help of your service, thank you soooooo much."

Cynthia, Akwa Ibom State University .
• "Sorry, it was in my spam folder all along, I should have looked it up properly first. Please keep up the good work, your team is quite commited. Am grateful...I will certainly refer my friends too."

Elizabeth, Obafemi Awolowo University
• "Am happy the defense went well, thanks to your articles. I may not be able to express how grateful I am for all your assistance, but on my honour, I owe you guys a good number of referrals. Thank you once again."

Ali Olanrewaju, Lagos State University.
• "My Dear Researchwap, initially I never believed one can actually do honest business transactions with Nigerians online until i stumbled into your website. You have broken a new legacy of record as far as am concerned. Keep up the good work!"

Willie Ekereobong, University of Port Harcourt.
• "WOW, SO IT'S TRUE??!! I can't believe I got this quality work for just 3k...I thought it was scam ooo. I wouldn't mind if it goes for over 5k, its worth it. Thank you!"

Theressa, Igbinedion University.
• "I did not see my project topic on your website so I decided to call your customer care number, the attention I got was epic! I got help from the beginning to the end of my project in just 3 days, they even taught me how to defend my project and I got a 'B' at the end. Thank you so much researchwap.com, infact, I owe my graduating well today to you guys...."

Joseph, Abia state Polytechnic.
• "My friend told me about ResearchWap website, I doubted her until I saw her receive her full project in less than 15 miniutes, I tried mine too and got it same, right now, am telling everyone in my school about researchwap.com, no one has to suffer any more writing their project. Thank you for making life easy for me and my fellow students... Keep up the good work"

Christiana, Landmark University .
• "I wish I knew you guys when I wrote my first degree project, it took so much time and effort then. Now, with just a click of a button, I got my complete project in less than 15 minutes. You guys are too amazing!."

Musa, Federal University of Technology Minna
• "I was scared at first when I saw your website but I decided to risk my last 3k and surprisingly I got my complete project in my email box instantly. This is so nice!!!."

Ali Obafemi, Ibrahim Badamasi Babangida University, Niger State.
• To contribute to our success story, send us a feedback or please kindly call 2348037664978.
Then your comment and contact will be published here also with your consent.

Thank you for choosing researchwap.com.