NAME OF THE INSTITUTION: NYERI NATIONAL POLYTECHNIC

TITLE: UPGRADING KINAMBA MWENJE ROAD INFRASTRUCTURE TO

BITUMINOUS STANDARDS

STUDENTS NAME: JAMES MWANGI MAINA

INDEX NUMBER: 2021150414

SUPERVISORS NAME: Mr. Thumbi

EXAMS SERIES: JULY SERIES

This report is submitted in partial fulfilment of the award of the Diploma in Civil

Engineering from The Nyeri National polytechnic

DECLARATION

I declare that this is my original work and it has never been presented anywhere else by

anybody in award of any academic certificate in any other institution.

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SUPERVISORS

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Acknowledgement

I want to take a moment to thank everyone who helped me put together this project. A special

shoutout goes to my supervisor Mr.Thumbi whose encouragement and guidance kept me

motivated and on track throughout the entire process. Lastly, I am also incredibly grateful to

my parents their financial support and constant encouragement have meant the world to me

and pushed me to aim higher than I ever thought possible. The list is long but I will not end

my special thanks without mentioning my great friend Madona for not only supporting me in

writing the project but also being available always for me.
DEDICATION

I dedicate this project to my parents, my two sisters, my friend Madonna and all aspiring to

the field of Civil engineering.

CHAPTER 1: INTRODUCTION

1.1 Background

Transportation infrastructure plays a vital role in the economic and social advancement of
any region. Roads in particular are among the most critical infrastructure components
because they connect people to essential services such as education, healthcare and
marketplaces while also enabling the movement of goods and services. In developing
countries like Kenya, many rural and semi-urban roads remain in substandard condition with
gravel or earth surfaces that deteriorate rapidly under heavy rainfall or increased vehicle
usage.

One such road is the Kinamba-Mwenje Road a key link between communities in the area and
various economic centres. The road serves multiple purposes including the transportation of
farm produce by farmers, access to education by school children and facilitation of daily
operations by business owners. However its current state is far from ideal. Being a gravel
road it is prone to becoming muddy and impassable during rainy seasons. Poor drainage and
lack of regular maintenance exacerbate these conditions often making travel along this route
difficult and unsafe. The importance of upgrading Kinamba-Mwenje Road cannot be
overstated. Transitioning it from gravel to a bituminous surface would vastly improve its
durability, reduce travel times and lower vehicle operating costs. Bituminous roads are
known for their strength, weather resistance and smoother surfaces which significantly
enhance user comfort and safety. Additionally a well-paved road would attract investment
opportunities, promote regional development and uplift the living standards of the local
population.

1.2 Problem Statement

The current condition of the Kinamba Mwenje Road presents serious transportation and
development challenges for the people who rely on it daily. As an unpaved earth and gravel
road it is particularly vulnerable to weather extremes especially heavy rains that cause
flooding, erosion and the formation of deep ruts and potholes. These conditions often render
the road impassable isolating communities and hindering access to essential services such as
schools, hospitals and markets.During the rainy season, vehicles frequently get stuck or avoid
the route entirely forcing users to take longer more expensive detours. This leads to increased
costs for transporting agricultural produce and goods delays in service delivery and a general
decline in the quality of life. In dry conditions dust becomes a major problem, affecting
visibility and posing health risks to nearby residents. Despite its strategic importance
Kinamba-Mwenje Road has not received the attention it deserves in terms of maintenance or
upgrades. Most repairs carried out are short-term and do little to address the underlying
issues. Without a well-structured and properly implemented solution these challenges are
bound to persist and possibly worsen with increased usage.

1.3 Objectives
1.3.1 General Objective To evaluate and design a sustainable upgrade of Kinamba-Mwenje
Road to bituminous standards to improve its usability, safety and socio-economic impact.

1.3.2 Specific Objectives

 To assess the current physical and structural condition of Kinamba Mwenje Road.
 To identify the most suitable bituminous pavement design that meets local
requirements.
 To determine the types, sources and quantities of materials needed for the upgrade.
 To analyse drainage issues and propose effective water management solutions.
 To estimate the total construction costs and outline future maintenance strategies.

1.4 Research Questions

 What is the present condition of the Kinamba Mwenje Road and what are its major
deficiencies?
 What type of pavement structure is best suited for the upgrade?
 What materials are required and how can they be sourced efficiently?
 What drainage interventions are necessary to ensure road durability?
 What are the projected costs involved in upgrading the road?
 What maintenance practices should be adopted to prolong the road’s service life?

1.5 Research Justification

The upgrade of Kinamba Mwenje Road goes beyond infrastructure improvement; it touches
on economic empowerment, community development and social inclusion. With better roads
farmers can transport produce more efficiently, students can attend school without delays and
emergency services can reach remote areas faster. Improved road access also enhances trade
by opening up markets and attracting investors who would otherwise avoid areas with poor
infrastructure.

1.6 Research Significance

The study contributes to the broader field of civil engineering by addressing practical
challenges in rural road design and construction. It provides a case based framework for
infrastructure planning, especially in resource limited settings. Government departments,
donor agencies and development organizations can use the insights generated to design cost
effective and durable rural transport networks.

1.7 Limitations of the Study

This research is likely to encounter several limitations. Financial constraints may restrict the
extent of on-site investigations such as soil testing and traffic surveys. Time limitations could
affect the comprehensiveness of the data collection and analysis phases. Additionally
unpredictable weather conditions particularly during the rainy season may hinder access to
certain parts of the road for accurate assessment. Access to the latest technical data or
engineering tools may also be limited due to resource availability.

1.8 Scope of Study

The scope of this study is confined to the Kinamba-Mwenje Road. It covers technical
evaluations including condition assessments, pavement design, and materials estimation,
drainage planning and cost analysis. The study will focus on providing practical design
recommendations based on engineering standards and local needs. Broader issues such as
environmental impact assessments, land acquisition challenges or national level policy
formulation are outside the scope of this project although they may be acknowledged for
contextual relevance.
CHAPTER 2: LITERATURE REVIEW

2.1 Discussion of Current Design or Studies

The design and construction of roads have significantly advanced over the years, with current
practices emphasizing durability, cost efficiency, user safety and environmental
responsibility. A road's performance largely depends on careful planning, sound engineering
principles and the appropriate use of materials. In recent times, the construction of
bituminous roads has become increasingly preferred due to several benefits such as smoother
driving surfaces, reduced dust emissions, improved vehicle traction and better resistance to
varying weather conditions.

Modern road design takes into account multiple factors including projected traffic volumes,
axle load distributions, subgrade soil conditions and hydrological data to produce roads
capable of withstanding expected stresses. Particularly in rural development contexts such as
in many parts of sub-Saharan Africa bituminous roads are now seen as more sustainable
alternatives to gravel roads. They require less frequent maintenance and typically last longer
making them a cost-effective option in the long term. In Kenya, the Ministry of Transport and
Infrastructure has developed comprehensive guidelines for road construction detailed in its
Road Design Manuals (Volumes I and II). These manuals set out standards for tasks such as
preparing the subgrade, constructing base layers, applying asphalt surfacing and
implementing proper drainage systems. They also stress the importance of safety measures
including road signs, guardrails and pedestrian paths.

Globally, institutions like the American Association of State Highway and Transportation
Officials (AASHTO) and the UK’s Design Manual for Roads and Bridges (DMRB) offer
widely recognized standards that are often adapted to fit local conditions in developing
countries. The application of technology such as computer-aided design (CAD) and
Geographic Information Systems (GIS) has further enhanced the precision and efficiency of
road planning and construction. Examples from counties like Meru, Machakos and Baringo in
Kenya illustrate the tangible benefits of upgrading gravel roads to bitumen. These regions
have seen noticeable improvements in trade, reductions in transport costs and better school
attendance after such projects highlighting the broader socio-economic impact of quality road
design.

2.2 Discussion of Existing or Past Studies

Several studies have highlighted the crucial role rural roads play in improving livelihoods,
boosting local economies, and facilitating access to vital services. Reports from the Kenya
Rural Roads Authority (KeRRA) document how improved road conditions positively affect
agricultural output, market access and service delivery. A 2017 study, for instance reported
significant gains in farm incomes and market connectivity in areas where roads were
upgraded from gravel to bitumen. In a broader regional context the World Bank has observed
that rural road development in East Africa often results in better mobility for groups such as
women, children and the elderly. Improved roads also lead to easier access to healthcare
facilities, better school attendance and more diversified local economies due to enhanced
logistics and mobility. The African Development Bank (AfDB), in evaluating road projects in
Ethiopia, Uganda, and Kenya, stressed the importance of involving local communities in the
planning and execution of road works. Projects that engaged residents during design and
construction phases were found to be more effective in terms of long-term usage and
maintenance. Academic institutions in Kenya including the University of Nairobi and Jomo
Kenyatta University of Agriculture and Technology (JKUAT) have contributed to this area
through detailed studies on the engineering performance of bituminous roads. These include
investigations into soil strength, pavement layer behaviour and the overall cost-effectiveness
of road upgrades.

2.3 Critique of Past Studies

While the insights gained from past studies are invaluable several limitations reduce their
practical utility. Most notably technical aspects such as subgrade challenges, material quality
control and the efficiency of drainage systems are often underreported. These omissions
make it difficult to replicate successes or understand the root causes of failures. Many of
these studies also fail to include long-term performance data. Roads that initially perform
well may deteriorate rapidly if not properly maintained or if built with inadequate materials.
Without data collected over several years it is difficult to assess how sustainable these
improvements truly are.

Another issue is the tendency to generalize rural road conditions ignoring significant
differences in topography, rainfall patterns, soil composition and local construction practices.
As a result, solutions that work well in one area may not be applicable elsewhere leading to
less effective or even failed projects. Additionally considerations related to climate change
are often missing. With extreme weather becoming more frequent, roads need to be designed
with climate resilience in mind. Without incorporating such measures like improved drainage
systems or flood-resistant materials road infrastructure remains vulnerable to environmental
stress.

2.4 Summary of Gaps Identified in Past Studies

 A lack of focus on engineering challenges specific to local terrains and environments.

 Insufficient monitoring and evaluation of road performance after completion.
 Incomplete documentation of drainage solutions and their role in road longevity.
 Weak planning for sustainable and routine maintenance after construction.
 Minimal inclusion of feedback from road users and community stakeholders.
 Failure to integrate climate change resilience into design strategies.
 Lack of post-construction quality control audits and independent assessments.