Description
CHAPTER ONE
1.0 INTRODUCTION
The catalogue on road defects (1992) refers to road defects as the visible
evidence of an undesirable condition in the pavement affecting serviceability,
structural condition or appearance. The definition of a "road defect" includes any
part of a road, highway, or construction site that does not meet the regulations
for a safe road. In Nigeria the defects that most often cause injuries to people or
damage to vehicles include: inadequate road shoulders, lanes that are uneven,
pavement that is uneven, improperly marked signs, malfunctioning stop lights,
construction negligence, and municipal negligence. These leads to accidents on
Nigeria roads which lead the national emergency agency NEMA to put up a
programme that engaged the competent hands from other stake holders such as
the Nigerian police, Nigerian army, Nigerian security and civil defense corps,
federal road safety commission, National air space management authority,
Nigerian red cross, the states ministries of health and environment. For the
programme, national and state emergency agencies were to train the volunteers
(Onwubiko 2010). NEMA also did a study on the major causes of accidents across
the country in collaboration with the federal road safety commission in close
partnership with members of some state emergency management agencies in
some flash points like Tafa junction, Forest/ Mararaba to Jos in Kaduna state and
made recommendations to some state governments on the urgent need to
decongest some major federal highways which passed through these states and
are now used by heavy duty vehicles drivers as transit camps thereby constituting
veritable sources of road disaster. From these studies it indicated that the
deplorable conditions of the roads contribute to high level of accident on the
roads. Onwubiko (2010) stated that Nigerian roads were death traps. In the
developing world which includes Nigeria, road network is the most developed
transport mode and the vastest in usage. The Nigerian government over the years
has tried to construct and rehabilitated the roads. Considerable interest has been
shown by the government to road investment (see table2). The issue has been
the extent these interests has been driven to achieve the desired result.
According to Oguara(2010), roads represent the major areas of investment in
transportation and are the most dominant travel mode accounting for over 90%
of passenger and goods transport in Nigeria. One of the main problems of road
work in Nigeria is the lack adequate informational data on the Nigerian roads.
Some studies have been done on the state of Nigerian roads. Ette (2010) stated
that there was a road net work study that was commissioned in 1998/99. This
study covered all inters- urban roads which had a traffic of more than 30
vehicles/day and a total length of around 53,000km. Urban roads were not
included in this study. The outcome of the study is shown in table 1 below. The
problems of the Nigerian roads are looked into in this paper and their causes
analysed with the proffering of solutions to these problems.
1.2 OBJECTIVES OF THE STUDY
The major goal of this research is to investigate the causes leading to the early
deterioration of the highway (road) pavement and the remedial approach to
ameliorate the current situation.
1.3 SCOPE OF THE STUDY
Highway pavement failure occurs when it can no longer perform its traditional
function of carrying vehicles and people from one location to another in safety
and comfort before the anticipated design life.
Usually highway pavement failure of Nigeria roads results in frequent road
accidents with loss of life and properties, high transportation costs of goods and
services, high maintenance costs of vehicles and increase in travel time.
1.3 CLASSIFICATION OF NIGERIAN ROADS.
Nigeria has about 200,000 km of roads spread all over the country. These roads
are made up of over 32,000
FEDERAL ROADS
In one of its publications in June 2011, the federal ministry of works reported that
it had over thirty five thousand kilometres of federal roads and bridges in the
thirty six states of the federation and the federal capital territory, Abuja (see table
4). These roads are divided into the federal trunk ‘A’ roads and the federal trunk
‘F’ roads. The federal trunk ‘A’ roads are those under the federal government
ownership and they are developed and maintained by the federal government
while the federal trunk ‘F’ roads are those that were formerly under the state
ownership, but were taken over by the federal government, with a view to
upgrading them to federal highway standards (Nnanna etal 2003). The faults on
most of the Nigerian federal roads are; depressions on the road surfaces,
presence of pot holes and cracks, development of gulley due to erosion, washing
away of the road shoulders, faulty street lights, faulty drainage systems , faulty
traffic signals and wiping off of pavement markings.
STATE ROADS
The state roads are classified as the state trunk ‘B’ roads. These are the roads
under the ownership and management of the various state governments.
LOCAL GOVERNMENT ROADS
These are classified as the local government trunk ‘C’ roads. They are the roads
under the ownership and management of the local governments in the country.
These roads are divided into the urban, rural and village access roads.
URBAN ROADS
In Nigeria, these are the roads that are in the urban areas. They account for over
twenty one kilometres of Nigerian roads. They include township streets, lanes,
cul-de-sac and avenues. Most of these roads are tarred while some are still
untarred. In the state capitals the advanced urban roads posses traffic facilities
like street lights, drainage facilities, pavement markings and traffic signals. In this
country, the main faults on most of our urban roads are almost the same as the
ones on the federal and state roads; they are; depressions on the road surfaces,
presence of pot holes and cracks, development of gulley due to erosion, washing
away of the road shoulders, faulty street lights, faulty drainage systems, faulty
traffic signals and wiping off of pavement markings.
RURAL ROADS
In Nigeria, rural roads account for over 72,000 km of roads in the country. These
are roads that are found in the remote country parts of the nation. They are
mainly earth roads, but with recent developments in the rural areas some of them
are now lightly tarred. Here, most of the faults on our urban roads are also
available on our rural roads. Faults like the depression of the road surfaces,
presence of potholes, cracks, gulley and the wearing away of the road surfaces
are rampant.
VILLAGE ACCESS ROADS
In the local governments these are minor roads that provide access within the
various villages we have in the country. They are mainly earth roads. The level of
under development of these roads reduces them to the level of foot paths. The
village access roads account for 35000 km of Nigerian roads (see table3).