UMUTARA POLYTECHNIC

FACULTY OF TECHNOLOGY

DEPARTMENT OF BUILDING AND CONSTRUCTION TECHNOLOGY

A STUDY ON ROAD TRAFFIC SAFETY (CASE STUDY NYAGATARE TOWN)

BY

NIYONZIMA JEREMIE TUP/0044/MG/10

GUMYUSENGE IMMACULEE TUP/0068/MG/10

Project proposal

Submitted to the faculty of technology

department of building and construction technology

in partial fulfilment of the requirements

for the degree of

Bachelor of technology

In

Building and construction technology

December, 2012

Supervisor

Mr. KIPTUM Clement Kiprotich

Nyagatare, 2012

DECLARATION

We declare that, the final project entitled, “A STUDY ON ROAD TRAFFIC SAFETY

(CASE STUDY NYAGATARE TOWN)” is our original work and has never been submitted

to any University or other Institutions of Higher Learning. It is our own research whereby

other scholar’s writings were cited and references provided. We thus declare this work is ours

and was completed successfully under the supervision of Mr. KIPTUM Clement Kiprotich.

Signature

NIYONZIMA JEREMIE ………………….

GUMYUSENGE IMMACULEE …………………

ABSTRACT

Nyagatare is a small town but now is experiencing an increase of traffic volume like

motorcycles, vehicles and other road user like pedestrians. The current condition of road,

road marking systems, road signing and poor lighting make roads unsafe and put in danger

the road users who lose their live during accidents. It is possible to reduce road accident rate

and severity by adopting and enforcing proper safety measures. This study was carried out to

evaluate the situation of road condition, marking systems and road signs in Nyagatare Town

through observations.

CHAPTER I: INTRODUCTION

I.1. background of the study

Road traffic safety refers to methods and measures for reducing the risk of a person using the

road network being killed or seriously injured. The users of a road include pedestrians,

cyclists, motorists, vehicles and their passengers (forum i. t., 2008)

Road traffic crashes are one of the world’s largest public health and injury prevention

problems. According to the World Health Organization (WHO), more than a million people

are killed on the world’s roads each year.

In Rwanda, 1,510 accidents were recorded in the first quarter of last year (between January 1

and April 30) alone. In all these accidents, some 136 lives were lost while another 977 people

suffered injuries. Going by this statistics, an average of one person is killed on Rwanda’s

roads each day, and if this trend continued, more than 365 will be killed by the end of this

year (rwanda focus, 2012)

Statistics show that motorcycles are responsible for 80 per cent of road accidents recorded

annually, especially in Kigali city. Taxi –Motos are the quickest and most preferred means of

transport especially in Kigali city, they are liked for their ability to beat traffic and to access

difficult areas (Rwanda national police, 2012).

Nyagatare town is located in Eastern province and is experiencing an increase of traffic

volume especially motor cycles, taxis, pedestrians etc. This study was carried out to evaluate

the situation of roads traffic safety in Nyagatare Town and find out the engineering measures

for improving the road traffic safety in Nyagatare Town.

I.2. Problem statement

Roads accident can be the leading cause of injury and even death in Nyagatare Town and

because it so disproportionately strikes the young, it also is the leading cause of lost years

of productive life. Nyagatare is a small town but is experiencing an increase of traffic volume

especially motor cycles, taxis, pedestrians. Motor vehicle injury is overwhelmingly the

largest contributor to these losses. In Nyagatare Town, paved roads are characterised by the

lack the road markings, signs, humps to control speed and insufficient lighting and on the

other hand, unpaved road are not well maintained and poor lighting. Safety improvement

requires progress toward reducing the crash experience of drivers, passengers, and other

vulnerable road users.

This study was carried out to evaluate and analyse the situation of roads traffic safety in

Nyagatare Town and find out the engineering measures for improving the road traffic safety

in Nyagatare Town.

I.3. Objectives

1.3.1 Main objective

The main objective of this study is to evaluate and analyse the roads traffic safety in

Nyagatare Town

1.3.2 Specific objectives

To come up with engineering measures for improving the roads safety in Nyagatare Town

1.4 Assumptions

Lack of road signing, poor lighting and bad roads contribute to the poor road safety .

CHAPTER II: LITERATURE REVIEW

2.1 introductions

This chapter reviews literature on road safety in the world and Rwanda and gives engineering

measures needed.

2.2.1 Definitions of common terms used.

- Roadway: It is a highway over which a public has a right of way. It includes the following

mainly:

Foot path: a high way over which the public have a right of way on foot only.

Foot way: is a way within a highway which also comprises a carriage way and is a

way over which the public has a right on foot only. It is either directly alongside the

carriage way or generally parallel to it but separated from it by a verge.

Number of Lanes

Lane Width

Surface Condition

- Vertical Alignment: The vertical profile of a highway or its vertical alignment consists of a

series of straight gradient and circular, or, more usually, parabolic vertical curves.

Grade on Tangent (%)

Grade on Curve (%)

Sight Distance (Feet/m)

- Horizontal Alignment: Consists of a series of interconnected straights, transition curves and

circular curves, although cubic, spline layouts may also be designed using computer-aided

design packages.

The chosen alignment for a road depends on a variety of economic, operational,

environmental and other factors although the two issues of driver comfort and safety are of

particular importance in the design of individual elements of the alignment.

Degree on Curve

Shoulder

Width (Foot/m)

Surface Condition

Traffic Control

Delineator

Guide Sign

Lighting

Marking

2.2 road safety

Road traffic safety refers to methods and measures for reducing the risk of a person using the

road network being killed or seriously injured. The users of a road include pedestrians,

cyclists, motorists, vehicles and their passengers (forum i. t., 2008)

Road traffic crashes are one of the world’s largest public health and injury prevention

problems. The problem is all the more acute because the victims are overwhelmingly healthy

prior to their crashes and more than a million people are killed on the world’s roads each

year, according to the World Health Organization (WHO).

2.3 road safety in Rwanda

In Rwanda, 1,510 accidents were recorded in the first quarter of this year (between January 1

and April 30) alone. In all these accidents, some 136 lives were lost while another 977 people

suffered injuries. Going by this statistics, an average of one person is killed on Rwanda’s

roads each day, and if this trend continued, more than 365 will be killed by the end of this

year (Rwanda focus, 2012)

Statistics show that motorcycles are responsible for 80 per cent of road accidents recorded

annually, especially in Kigali city. Taxi –Motos are the quickest and most preferred means of

transport especially in Kigali city, they are liked for their ability to beat traffic and to access

difficult areas (Admin, 2012)

Ten years ago Rwanda had one of the worst road-safety records in the world. But once the

government recognized that making roads safer could help with the rehabilitation of a nation

traumatized by the 1994 genocide, its efforts have won international acclaim.

This transformation has been far from easy to achieve, however. A World Bank situation

report, commissioned in 1996, concluded that one accident was taking place every two and a

half hours on Rwanda’s roads, almost all of which left people injured and 10% of which

resulted in deaths (world hearth organization, 2007)

2.4 Characteristics of Road Geometrical Design in road safety

Research has shown that careful design and maintenance, with well-designed intersections,

road surfaces, visibility and traffic control devices, can result in significant improvements in

accident rates (Joan, 2008).

Some of the primary geometric design elements that can affect on highway safety are

carriageway, grade, horizontal curvature, shoulder, median (Babkov, V.F ,1975).

Relationship between some characteristics of these elements and traffic accidents, including

studies made in different countries are given below.

- Carriageway characteristics: At the end of many studies it is proven that the width of the

road carriageway has an obvious effect on accidents. As carriageway width increases, traffic

accidents decrease. This relationship is more important

in developing countries than in developed countries.

Also in many studies, other characteristics like the number of carriageways of a road, the

number of intersections on it and its number lanes are related with road safety.

These studies have shown that the safest road is a divided, multi-lane road with interchanges;

and the level of safety decreases on three-lane roads.

- Grade: Although different results were obtained in different studies, it is known that as

vertical grade increases, accident rate increases, too.

On the other hand, at points where high-slope sections end in low-radius horizontal curves,

the numbers of accidents are high.

- Shoulder characteristics: Studies show that there is a relationship between shoulder width

and traffic accidents. As width is increased, the number of accidents are decreased

It is found that when the shoulder surfaces are not paved and there is a shoulder drop-off road

safety gets lower.

- Characteristics of horizontal curves: The premier factor in accidents happening inside

horizontal curves is radius. As radius is decreased, the number of accidents happening inside

horizontal curves are increased. Similarly, as horizontal curve level of curvature is

increased number of accidents increase.

Median characteristics : Presence of a median on a road contributes positively to road

safety. The effect of the median width on safety increase is seen in. Moreover, studies prove

that medians designed at a lower altitude than the pavement are better for safety than medians

designed at a higher altitude.

2.5 Role of geometric Design elements in roadway safety

Geometric design is an aspect of road design dealing with the visible dimension of a

roadway. This one can be dictated, within the economic limitations, by the requirements of

traffic and includes the design elements of horizontal and vertical alignment, sight clearance,

cross-section components, lateral and vertical clearances, intersection treatment, and control

of access. (L.R.KADIYARI, 1997).

The safe, efficient and economic operation of a road is governed to a large extent by the care

with which the geometric design has to be worked out.

The following elements must be considered when carrying out the geometric design of a

road:

Horizontal alignment:

Horizontal alignment deals with the design of the directional transition of the road in a

horizontal plane. A horizontal alignment consists, in its most basic form, of a horizontal arc

and two transition curves forming a curve which joins two straights. In certain situations the

transition curve may have zero length.

The design procedure itself must commence with fixing the position of the two straight lines

which the curve will join together. The basic parameter relating these two lines is the

intersection angle.

Vertical alignment:

Once the horizontal alignment has been determined, the vertical alignment of the section of a

road in question can be addressed. Again, the vertical alignment is composed of a series of

straight-line gradients connected by curves, normally parabolic in form (see Fig. 1). These

vertical parabolic curves must therefore be provided at all changes in gradient. The curvature

will be determined by the design speed, being sufficient to provide adequate driver comfort

with appropriate stopping sight distances provided.

Figure 1 .Example of typical vertical alignment.

Cross-section:

The pavement designer must develop the most economical combination of layers that will

guarantee adequate dispersion of the incident wheel stresses so that each layer in the

pavement does not become overstressed during the design life of the highway.

The standards to be chosen for these design elements are dependent on the criteria for the

geometric design controls including appropriate standards for cross-section.

Road width should be minimized to reduce the costs of construction and maintenance, while

being sufficient to carry the traffic loading efficiently and safely. The following factors need

to be taken into account when selecting the width of a road:

Classification of the road: a road is normally classified according to its function in the road

network; the higher the class of road, the higher the level of service expected and the wider

the road will need to be.

Traffic: heavy traffic volumes on a road means that passing of oncoming vehicles and

overtaking of slower vehicles are more frequent, and therefore the paths of vehicles will be

further from the centre-line of the road, so the traffic lanes should be wider.

Vehicle dimensions: normal steering deviations and tracking errors, particularly of heavy

vehicles, reduce clearances between passing vehicles; wider traffic lanes are needed when the

proportion of trucks is high.

Figure2. Type of cross-sections. Source: TRRL Overseas Unit (1988).

2.6 Engineering measures to improve road safety

2.6.1 Introduction

Accident occurrence is the result of the contribution of several factors associated with the

traffic system, namely: road user, road environment and vehicles. English and American

studies revealed that about 93% of all accidents involve human factors and nearly 33% are

associated with road environment (Treat, J. R. 1980). Finnish studies also revealed that the

road environment may lead to wrong driver behaviour, especially where road design

discontinuities prevent the driver from being able to predict the environment and situations

ahead. Road administrations have the responsibility to provide a road environment with the

best equilibrium between road infrastructure demand and drivers capabilities throughout all

the road life cycle (Cardoso, J.L, 2000)

2.6.2 Marking and Signing

Signs and markings can provide important information to improve road safety. They regulate,

warn and guide road users. By letting people know what to expect, chances are greater that

they will react and behave appropriately. Signs and markings need to be applied in a

consistent way, to be placed at logical locations, and be easy to understand and visible.

(European Union. 17 june 2007)

Information needed for orientation, operation and vehicle control is mostly visual. This is

why the driver must properly and timely receive relevant visual information, in order to allow

him to control the vehicle as well as ensure pedestrian safety. Vertical signs are devices

placed laterally to lanes or above them, with the proper support in each case.

Regulatory signs inform drivers about local impositions, and how they should act; danger

signs alert drivers for potential risky situations and information signs inform the drivers on

their itinerary, destiny and service locations.

Road markings are delineation systems installed on road pavement for:

• Vehicle position and movement control through visual information that identifies the

legal and safety limits of roadway.

• Driving direction regulation, changing lane and overtaking.

• Zone or lane identification, where manoeuvres are allowed, forbidden or mandatory.

• Lane discipline increment, particularly during night periods and adverse weather

conditions.

• Dangerous zones identification aid, like obstacles or pedestrian crossings.

-Longitudinal road lines define the road and lane limits. They can be continuous or

discontinuous, white (slightly silvered if they are reflector) or yellow in case of work zone

application.

-Edge lines are used to mark the carriageway limits. They are quite effective in guiding under

bad atmospheric conditions, or when shoulders are small or nonexistent. They are particularly

effective when applied simultaneously with the axial line, since they can increase lateral

restriction sensation and also contribute for lower speeds. Their colour should be the same as

the one of the road line that they are replacing or complementing. In order to be seen, they

can be internally-illuminated or retroreflective. In any case, they must simulate the effect of

traditional road marking. By its application average accident reductions of 10 to 40% may be

achieved (Elvik, R.; Vaa, T, 2004).

-Marker posts may be used to improve road delineation, especially under low visibility

conditions. This measure is particularly effective in roads without any marked limits, and is

able to improve from 30 to 40% in accident reductions (Ogden, K. W. 1996).

-Lane reduction arrows are obliquely placed on the lane that is about to end and warn the

drivers for the need to change lane. For a smooth transition, lane reduction arrows should be

placed before the transition zone and be repeated until the end of the lane.

-Chevron markings are inverted “V” shaped yellow markings placed with regular spacing in

the middle of traffic lanes. These markings are designed to improve road safety through the

encouragement of an inter-vehicular minimum distance practice.

2.6.3 Roadside improvement

Roadside plays a primordial role in what concerns to occupants of uncontrolled vehicles,

since if adequately designed, it may prevent a run-off-road manoeuvre from ending up as a

serious accident. Roadside areas provide space for parking broken vehicles, as well; besides

that, they can complement road functions, namely by integrating the road infrastructure in the

environment, creating a positive psychological feeling in vehicle occupants.

At the design level, obstacle free areas should be considered. In those areas, which include

Shoulder and medians, it should not be allowed to place any kind of obstacles that may put

into danger the occupants of uncontrolled vehicles (Cardoso, J.L, 2000).

Side slope is one of the factors that may affect the possibility for an uncontrolled vehicle to

overturn and for the driver to be unable to safely recover vehicle control.

Whether the side area is an embankment or an excavation, it is important to have a low slope

and the rounding of breaking points that may contribute to the loss of vehicle control, since

these are the sites where the vehicle tends to loose ground contact. Medians separate traffic

flows with opposite directions. They are also considered recovery areas

for uncontrolled vehicles and for emergency stops. Being so, they should be clear and have a

minimum with of 20 m. However, since this is not always an economic solution, smaller

medians may be adopted, if they are properly equipped with drainage organs and safety

barriers, depending on traffic volume. Sometimes medians are also equipped with antiglare

screens to mitigate dashing risk caused by vehicle head lights running on opposite direction.

Occasionally, these screens are obtained with vegetation (Ogden, K. W. 1996).

The shoulder may be used for emergency manoeuvres of uncontrolled vehicles area and for

emergency stopping, immobilized vehicle parking and for pedestrian and cyclist use. The

shoulder structure also provides lateral support to the road and pavement.

Shoulder area should be clearly separated from the carriageway by means of edge lines.

Shoulder width should not be too high to deter drivers from circulate in it; it should not be

very narrow either, because this would reduce its effectiveness.

In what concerns roadside fixed objects that might be a danger for some drivers of

uncontrolled vehicles, the first possible solution should be the removal of the obstacle.

However, if that isn’t possible, there are other solutions, such as the removal to a more distant

location or the use of break-away posts. Only if none of these options is possible, the

application of safety barriers should be considered (Ogden, K. W. 1996).

2.6.4 Anti-skidding pavement surface layer application

The application of a new layer can only be considered a low cost engineering measure if it is

applied in restricted areas. Its consideration on sharp curves, near pedestrian crossings,

intersections or roundabouts with a high number of run-off-road accidents, can be very

advantageous. (Ogden, K. W.1996).

2.6.5 Improvement of sight conditions

Stopping sight distance is the minimum distance needed for a vehicle, running at a specific

speed, to stop, after its driver perceived an obstacle on the roadway. This distance is very

important for road safety, since it has to increase for higher speeds. To maintain an

appropriate road safety level, suitable speed limits must be set, to assure that there is no

visual obstruction by the vegetation and that access to the road doesn’t occur at inappropriate

places.

Drivers of vehicles that change direction on intersections may have to take quick decisions on

when to move forward, as a function of road design and conflict identification. These

decisions are made in a matter of seconds, and any misinterpretation can be a factor for

accident causation. As so, visibility triangles and intersection design are important road safety

issues. Several studies reached the same conclusion: accident rates grow proportionally to

small decreases in visibility distance. A 10 to 60% accident number reduction was obtained

by the improvement of visibility conditions, with relation to head-on collisions and lateral

collisions on turning movements (Ogden, K. W.1996).

Fig 3: Example of a typical sight distance on a curve

Source: A Policy on Geometric Design of Highways and Streets, AASHTO, 2004. Chapter 3 Elements of Design

2.6.6 Traffic channelization

Traffic channelization aims at reducing conflicts between vehicles and pedestrians. It

facilitates correct trajectory selection, capacity increase and traffic control and maximizes

driver/road communication. It also reduces the number of decisions that a driver must deal

with at a certain place, giving him time to think on the next decision and then act accordingly.

In single carriageway two way-two lane roads, there are two traffic channelization solutions:

the first is to introduce turning lanes (left or right) which are secure places for vehicles that

are going to turn, thus reducing risk of accident and encouraging drivers to wait for the right

time to turn; the second solution is to use shoulders as an additional lane for overtaking

vehicles that are waiting to turn left.

This solution is not very expensive, since, if shoulders are already paved, it’s only necessary

to paint the corresponding markings. Traffic canalization measures may contribute to

reductions (15% to 57 %) in the number of personal injury accidents (Elvik, R.; Vaa, T.2004).

2.6.7 Maintenance

Maintenance of existing roads is necessary to keep them up to standard. Maintenance relates

to pavement, signs and markings as well as the road side. Maintenance plans based on

observation and measurement procedures ensure that the key safety features are never out of

order (European Union. 17 june 2007)

2.6.8 Quality assurance

It is important that road infrastructure be planned, designed and constructed with maximum

consideration of the safety effects. This applies both to new infrastructure and to

reconstruction schemes. An instrument for doing so is the road safety audit. In road safety

audits, road safety experts look at the potential safety problems in different stages of planning

and designing of an infrastructure project (European Union. 17 june 2007)

2.7 Non-engineering measures for improving the road safety

2.7.1 Road safety education

Road safety education is generally performed in a school setting, focusing on the different

transport modes and traffic roles that the pupils at different ages encounter actively or

passively. Whereas many countries advocate what is called permanent education, from the

cradle to the grave, in practice the majority of road safety education programmes are directed

at primary school children (European Union. 17 june 2007).

2.7.2 Road safety campaigns

Road safety campaigns as a stand‐alone measure generally don’t have a large effect on road

safety. However, campaigns are crucial as a support for other measures such as legislation

and enforcement. Campaigns generally aim to explain new legislation, to inform about a

specific road safety problem and why particular measures are necessary.

Some measures directly aim to change behaviour (e.g. not to speed, to use seat belts, to have

lights on your bicycle, etc.).

It is important that the message be short, clear and unambiguous. Furthermore, it is important

that a campaign make use of different media, e.g. bill boards, radio and television, leaflets,

etc., and is repeated several times( European Union. (17 june 2007)

2. 7.3 Adequate training of drivers

Increasing the number of driving lessons in the driving school, where the focus should be not

only on acquiring the skills of driving a car, but also those associated with the correct

behavior in traffic; tightening the conditions of access to the driving exam (especially the

psychological test), as well as the conditions of promoting it (increasing the number of tests

before obtaining the driving license) (forum i. t., 2008)

2.7.4 Traffic Law Enforcement

It is widely recognised that enhanced enforcement especially when it is targeted to speeding,

drink driving and non‐use of seat belts is a very important (and cost‐effective) way to achieve

substantial improvement in road safety within a relatively short period (European Union. 17

june 2007)

Conclusion:

The main causes generating accidents are speed, road condition, vehicle condition, bad

behaviours of drivers and pedestrians’ lack of discipline. It is necessary to adopt measures to

prevent road accidents, both by drivers and by pedestrians, and involve specialists in different

sectors: police, road administration, health, car production industry. It is possible to reduce

road accident rate and severity by adopting and enforcing proper safety measures.

Road safety is a major public health concern. So attention must be given on road safety

measures. Strict implementation of road safety measures reduces road accident injuries and

fatality.

CHAPTER III: METHODOLOGY

The purpose of this study was to evaluate and analyse the situation of roads traffic safety in

Nyagatare Town and find out the engineering measures for improving the road traffic safety.

The methodology used was observation to collect information from the field and Arc GIS

software to produce road network of the study area.

Another method was questionnaire in order to collect information from the road user about

what they think of road safety and what can be done to improve it.

3.1 Study area

The project road is located in Nyagatare town. The study was carried out on paved and

unpaved road. For paved roads, two types of pavements were observed: flexible pavement

and stone pavement. The road with flexible pavement is located from the junction under blue

sky Hotel connecting the road going to barija and another road with stone pavement going to

the car park. This road is the main road and starts from that junction going to ryabega and has

two lanes. Another part of road with flexible pavement starts at the junction under Nyagatare

Mtn centre and ends near the main gate of Umutara Polytechnic.

Road with stone pavement in the study is the one that passes under Nyagatare radio and ends

at the junction under blue sky to the main road.

For unpaved roads only two roads were concerned: The first road starts at the gate of

Umutara Polytechnic and ends near Catholic Church. The second road starts at the junction

going to barija and ends to the Police station.

3.2 Data collection method

This part highlights all the methods and procedures used in collecting data and gathering all

information concerning the research topic. It explains in details the data collected and

describes how this was done during the fieldwork. The first step was to select the roads for

the study. After selecting roads for the study, observation was mostly used to collect

information.

(1). Direct observation: the direct observation method involves the researcher to go to the

site and observe all events and recoding in order to analyze the data after.

(2).Other source of information: the data are collected from books, different reports and

internet.

3.2.1. Data sources

When conducting a research, two approaches are possible: either the information required is

already available and only needs to be extracted, or the information is not available and needs

to be collected. By using the first approach, the information is said to be collected using the

secondary sources while the second will be the primary sources.

In this research, both primary and secondary sources were used to collect required

information.

3.2.1.1 Primary sources

It was only field observations used to get information from the field.

3.2.1.1.1 Field observations

During this research Information was collected in four days, and the method used was

observation. During the work, the areas of interest were:

The quality of traffic signs, with respect to their need and to whether they are

Correctly placed or legible in the dark.

The quality of road markings, in particular whether they are visible or are consistent

with traffic signs.

The quality of traffic lighting, In particular the system used whether it is convenient

and efficient.

road condition

3.2.1.2 Secondary sources

As secondary sources, documents to highlight road safety in general and measures that can be

adopted to improve road safety in particular were consulted especially external sources which

include publications and/or reports from earlier researches on road safety.