ANALYZING THE IMPACT OF ROADSIDE TRADERS AND PUBLIC TRANSPORT VEHICLES ON NIGHTTIME TRAFFIC CONGESTION AT IKORODU GARAGE

CHAPTER TWO

LITERATURE REVIEW

2.0 Introduction

A review of literature is crucial as it shows a picture of the state of knowledge in the area of study. This chapter will consist of three sub-section which include the conceptual review, theoretical review and review of related studies in relation to the objectives of the present study.

2.1 Conceptual Review

2.1.1 Traffic Congestion

          Traffic congestion refers to the way the movement of vehicles is delayed by one another because of limited road capacity (Rahane & Saharkar, 2014). In simplerterms, road congestion occurs when the demand for traffic nears or surpasses the capacity of the road network (Raheem et al., 2015).Traffic congestion is one of the consequences of urbanization, it is a reflection of the urban development, housing, employment and cultural policies which influence where people live and work.Cities and traffic have developed hand-in-hand since the earliest large human settlements. The same forces that draw inhabitants to congregate in large urban areas also lead to sometimes intolerable levels of traffic congestion on urban streets and thoroughfares” (ECMT 2007:5).

          Rodrique et al. (2009) states that congestion can be perceived as unavoidable consequences of scarce transport facilities such as road space, parking area, road signals and effective traffic management. They argue that urban congestion mainly concerns two domains of circulation, passengers and freight which share the same infrastructure. Thus, traffic congestion condition on road networks occurs as a result of excessive use of road infrastructure beyond capacity, and it is characterised by slower speeds, longer trip hours and increased vehicular queuing. Downie (2008) also opines that traffic congestion occurs when the volume of vehicular traffic is greater than the available road capacity, a point commonly referred to as saturation. He describes a number of specific circumstances which cause or aggravate congestion. Most of such circumstances are concerned with reduction in the capacity of road at a given point or over a certain length, or increase in the number of vehicles required for the movement of people and goods. Downie (2008) further argues that economic surge in various economies has resulted in a massive increase in the number of vehicles that overwhelms transport infrastructure, thus causing congestion on roads in cities. Rodnique et al. (2009), note that congestion in urban areas is dominantly caused by commuting patterns and little by truck movement. They further attributed the causes of congestion to rise in population densities, road incidents and broken vehicles on the roads which restrict capacity of roads and impair smooth traffic flows.

          Another contributing factor to congestion as suggested by Herman (2001), cited Downie (2008) is parking. He is of the view that road parking, which consumes large amount of space has become a land issue that greatly inflates the demand for urban land, causing congestion in cities. He adds that high urban mobility rate also contributes to the congestion menace. The massive use of cars does not only have an impact on traffic congestion but also leads to decline in public transit efficiency, thereby creating commuting difficulties in cities. Indeed the overdependence on cars has tremendously increased the demand for transport infrastructure. Unfortunately the supply of transport infrastructure has never been commensurate with the growth of mobility needs. Consequently, several vehicles spend most of the time in traffic as a result of traffic space limitation (Yan and Crooks 2010).

Causes of traffic congestion differ slightly from place to place (Joseph, Ukpata, and Anderson, 2012) depending on a number of determinant factors which include the road network, land use pattern, traffic composition and the public transport policy. Identifying the causes of traffic congestion, Ogunsanya (2006) categorized it into physical, human and institutional matrix. Physical are transport infrastructures, while human refer to road users attitude, the regulatory institutions saddle with the responsibility of managing the road users and the infrastructure.  Aworemi et al (2009) and Bashiru and Waziri (2008) in a different studies in Lagos identified bad road condition and inadequate road infrastructure, others are poor traffic planning, drivers’ behaviour and lack of integrated transport system. Joseph et al (2012) identified Road intersections as major component of urban roads that are generally prone to generate traffic congestion while Momoh (2011) opine that over dependence in motor vehicle and lack of integrated transport system are responsible for the traffic congestion.

          Earlier studies (Popoola et al., 2012; Joseph et al, 2012; Aworemi et al (2009) and Bashiru & Waziri (2008) have place emphasis on road users perceptions and the role of regulatory agencies in traffic congestion analysis, little were the study on the physical infrastructure capacity vis-à-vis the existing traffic volume and characteristics.This study examines the adequacy of the highway in meeting the traffic demand for road space and traffic facilities in terms of capacity. Capacity of a facilities is defined as the maximum hourly rate at which persons or vehicles can reasonably be expected to traverse a point (Ajala, 2016) or uniform section of a lane or roadway during given time period under prevailing roadway, traffic and control conditions. It is express using passenger car unit (PCU) per hour.

Capacity can be expressed in three categories, first the basic capacity; second the possible/operating capacity and thirdly the practical/design capacity (Kadiyali, 2013). The basic capacity is the ideal number of vehicle that can pass a point on a lane of road where there is no impediments to traffic movement, while the possible/operating capacity is the maximum number of vehicle that can pass a given point on a lane or roadway under prevailing roadway and traffic operating condition. The practical or design capacity is the projected maximum number of vehicle that can traverse a roadway or a point taken into consideration the maximum traffic density that will not unreasonably cause delay, hazard or restriction  to the road users freedom to measure under prevailing roadway and traffic conditions. According to London ministry of Transportation (1966) as noted by Bruton (1985) the design capacity for a two lane road of 7.3m lane width is 1200 PCU/hour for two directional flows.

Understanding of capacity is very relevant to this study because it allows for comparison of the present operating capacity (Traffic Volume) with the design or practical capacity of the facilities to determine it adequacy or deficiently. The study investigates the main causes of traffic congestion associated with Nigerian urban roads in Ota. The city of Ota is one of the development pressure area of Ogun state (Ogun state, 2009), that witness high influx of vehicular traffic from both the national and international road corridor that significantly form the framework of the road network (Lagos-Abeokuta and Owode-Idi-Iroko expressway) of the city. Aside playing the role of primary roads linking cities, state and neighbouring countries, it also serve as access road and collector road in most cases, thus the attendant traffic challenges on the road.

2.1.2 ROADSIDE TRADERS

          Road side traders or street vendors are those who carry out business transaction on the road side. According to (Cross, 1998), streets traders offer to transact their business streets or pavement and may be viewed as a form of squatting (Bogoro, Ali, & Bukar, 2012). The traders display and market their wares or goods usually along roadsides of major roads, near government or big public establishments, within market places or during traffic congestion on busy roads. In some instances, the activities can be seen in illegal structures and abandoned buildings (Ouwamanam et al., 2007).

          Urban public spaces are designated social spaces that are open and accessible to all (Acheampong, 2019). Roads (including the pavement), public squares, parks, and beaches are typically considered urban public space. Urban public places are usually located in designated areas or within the private context (Solomon-Ayeh et al., 2007). They represent a vital contributor to the source of income for the urban poor, however, its contributions to economic development strategies for cities are largely ignored (Brown, 2006). Acheampong (2019) clearly states that street vendors are at the heart of the informal economic sector. Several contributing factors have been identified for the prevalence of street trading in Nigeria such; as unemployment due to public sector corruption, high inflation, low wages, unfavourable government policies, deplorable working conditions, widening gap between the rich and the poor, social exclusion and endemic poverty, which have made individuals, struggle to maintain their families (2007).

          In Nigeria, the persistence of street trading has obstructed and distorted city and urban planning and a major concern to government and private investors. Unfortunately, street trading has been described to be the commonest form of child labor in Nigeria and solace for out-of-school children (Ijadunola et al., 2017). Street trading has been implicated in different societal problems such as encroachment on the right of free movement by the traders, traffic congestion (Bhattacharya& Dey, 1997), defacement of the aesthetic appearance of the street and pedestrians injuries (Damsere-Derry, 2011). Environmental wastes generated by street traders lead to obstruction of drainage systems leading to flooding during rainfall, road dilapidation and health issues (Suleiman et al., 2013). The quality of items hawked deteriorates over time due to weather and other environmental variables and subsequent consumption poses public health concerns (Egwari et al., 2007).

2.1.2.1 The Characteristics of Street Vendors

          Acheampong (2019) clarified that street vendors are a major player in the informal economic sector. Thus, it is worthy of notice street trading share the same characteristics with other performing informal economic tasks. The major difference street trading has from other informal economic sectors is its propensity of being in every corner of the streets in the city and this makes it worthwhile to investigate and define those characteristics of street trading. Moreover, street hawking remains an integral part of every developing economy and targeted investment in it is expected to contribute to economic development especially when infused with innovation (Tarulevicz, 2018). Pillay (2004) argues street trading is the cheapest way of self-employment. However, this is not always the case because in some places street vendors are intermediaries and recruited by shop owners to market, sell and direct the prospective buyers to them. In all, it is not labor-intensive but depends heavily on the flexibility and marketing skills of the traders (Pillay, 2004). The easy entrance nature of street trading makes it attractive to women and children who need little formal education to ply the trade (Ajiboye & Oladiti, 2008). Teenage girls in rural sub-Saharan Africa are often the most affected in terms of exclusion in education because of street vending activities (Usman, 2010). Street traders use different structures, including mats, gunnysack, tables, tricycles, racks, wheelbarrows, containers, handcarts, and bicycle seats to display their goods. Those that cannot afford the different structures simply carry their wares on their hands, heads and shoulders, while others hang their commodities on walls, trees and fences. Some may opt to construction of temporary shades with suspended stands to display their goods on the streets (Mitullah, 2003).