1. business and industrial
2. construction

Autocorrelation of Urban Road and Drainage Developments in Environmental Valuation Analyses
Funlola Famuyiwa
Department of Estate Management,
Faculty of Environmental Sciences, University of Lagos
Lagos, Nigeria; [email protected]
ABSTRACT
This study aims at determining the nature and possible presence of autocorrelation in two physical infrastructure types (Road and Drainage developments) in various environmental amenity assessments. These two infrastructure categories are ideally planned simultaneously in public projects. In Nigeria, the failures of some road developments have been attributed largely to the lack of recognition of this critical factor in the decision making process, thereby jeopardizing long term durability and sustainability of projects. Thus, the relationship between these two infrastructure categories is tested using a survey of relevant studies that evaluate and or rank them within the scope of neighbourhood amenities. Results reveal variations in different studies albeit with significant levels of possible Heteroscedasticity and serial autocorrelation. Empirical findings from this research will help reinforce proper guidance in the direction of hitherto ‘overlooked’ issues in public development projects, especially in developing countries. This will help to further create a basis, and need for synchronized planning of these physical infrastructure categories and help reduce infrastructure investment wastages in developing countries. Also the selection of variables in similar research will be more intricately considered, ensuring validity of findings. 1
1. INTRODUCTION
One of the most significant aspects of urban and regional development systems is road infrastructure management. The nature and structure of road development networks provide a fair indicator of economic growth levels in communities. With the ever increasing demands and higher sophistication levels of modernization and technology, such investments carry the potential for further economic opportunities on both micro and macro scales. For example optimal performing roads enhance neighbourhood quality, which in turn positively impacts on real estate values within operative range. Generally, physical infrastructure is positively linked with productivity of urban economies and macro­economic development. Focus on urban infrastructure is particularly visible among developing countries, which are making serious efforts to enhance the productivity of their economies through improved provision of infrastructure. (Kulwant singh et al, 1996). Government authorities in various regions therefore, continue to plan and expand capacity in road development and other projects. In emerging and highly congested cities like Lagos, the astronomical and unprecedented population increase and resulting pressure placed on public physical infrastructure generally, has made qualitative road development planning even more critical on the agenda of various tiers of government.
Because urban development investments are usually long term, they require strategic planning especially in contemporary times where ‘sustainability’ is usually at the forefront of most project developments. Although, the eventual deterioration of such public utilities is inevitable, long and extended lifespans are desirable, so that general performance objectives ­ such as the accumulation of annuities adequate for creating financial vehicles for reconstruction at the end of the project life cycle ­ is attained. Also, so that sustainability requirements, etc are met. According to Akujuru (2004) due to long term and public benefit effects, infrastructure usually is capital intensive in nature and requires large scale investment. Therefore, investment management towards sustainability is of paramount importance.
Where infrastructure lifespans fall short of such expectations, projects are deemed unviable and unsustainable, and the implications of this in an economy are usually quite detrimental to all stakeholders, extending to the broader economy. The Ministry of Works and Urban development, Federal Planning Institute, Ethiopia (2006) submits that urban infrastructure in the developing world is often subjected to haphazard planning, disjointed implementation and poor post installation management. The ministry further explains that inadequate attention is given to (a) the interdependencies between infrastructure systems, (b) the urban functions to be served and (c) the sustainability of the facilities. The outcome is poor facility functions, early deterioration and unwanted settlement development, resulting in the wasteful use of scarce resources. This phenomenon of project failure after handing over/delivery is not uncommon, and in many urban centres in Nigeria for example, in as little as three months, a newly constructed or redeveloped road could be filled with large potholes, cracks, 2
and rendered unnavigable for motorists and even pedestrians. Several roads are known to have been constructed without due regard for this concept. Experts, have highlighted the lack of simultaneous drainage and road construction (or reconstruction) planning as a very major and significant oversight contributing to this phenomenon. According to Onoyan­Usina, Lazhi and Utomi­ushi (2013) a lot of Nigerian roads have inadequate drainage systems and deterioration often begins with the origin of cracks or pot holes on the road pavements either at the edges or along the drive way. Otegbulu and Adewunmi (2009) also mention that poor road and drainage conditions are common failures in Lagos and most places get flooded after heavy rainfalls due to blocked drainage facilities, and continuous flooding leads to road deterioration with deep pot holes. Clearly, many construction and development strategies used in Nigeria, contravene the recommended ideals of road development construction. This is exemplified technically and in industry.
An attempt is made in this study to determine if this technical and practical concept is replicated theoretically. This research therefore is aimed at assessing the empirical association and relationship that exists between Road developments and efficient drainage infrastructure from a pedagogical and objectivity based perspective. According to Johnson­Gardner (2007), the behaviour of consumers is frequently complex and therefore statistically “messy”. In the light of the aforementioned, there is thus the possibility that statistical inferences and results may not be in consonance with ‘widespread notions’ in industry. The implications of this could help provide a basis for further investigation of hitherto grey areas, directly related to an overlooked and unidentified issue in road and or drainage infrastructure planning in many developing countries. Therefore, this study will consider the following research statement. There is no statistical discordance in the direction and correlation of road and drainage infrastructure as independent variables when subjected to environmental valuation analyses.
Data obtained from a literature survey within the context of Lagos State, Nigeria and other developing countries is expected to help validate or refute the above statement. The results derived will emphasize the need for simultaneous planning of these two physical infrastructure categories. Similarly, it will serve as a guide for further research in the area of environmental amenity analyses, and variable choice and selection. The ‘behaviour’ of these two major variables in subsequent similar studies, will be better understood, providing insights as to the nature and validity of their statistical importance in inferential analyses particularly. From an urban governance perspective the scientific evidence provided will ultimately help in preventing wastages in public investment spending especially where funds are recouped through differential property based taxation. Finally, and based on the aforementioned, it will help to further minimize and or better understand the gap between theory and practice.
This section provides the synopsis, aim and justification of the study. The next section discusses the two major infrastructure categories under study. Next, the method and process adopted in fulfilling the aim of the study is laid out. 3
Subsequent sections discuss previous researches, and major highlights drawn and necessary conclusions encapsulating the major points under review.
2. ROAD AND DRAINAGE INFRASTRUCTURE: AN INTEGRATED THEORY
It is recognised that roads require drainage systems to deal with stormwater runoff. Therefore, drainage systems become an important and integral consideration in the planning and design of road infrastructure (Department of Transport and Main roads, State of Queensland, 2010). Designing for proper drainage of highway systems is crucial. Regardless of how well other aspects of a road are designed and constructed, adequate drainage is mandatory for a road to survive its entire service life. Excess water in the highway structure can inevitably lead to premature failure. ( Ksaibati, Khaled, Kolkman, and Laycee L. (2005). According to the department of Transport and Main Roads, drainage requirements are normally established during the identification of the project solution options and selection process..i.e. planning stage. While some developing countries are still grappling with this concept, many advanced nations are reinventing and applying dynamism to it. Guz, Morrison, McKenzie, Aukerman and Ralph (2008), report that in the United Kingdom, road engineers are being forced to respond to the new challenge of designing, owning and maintaining roads and related Sustainable Urban Drainage (SUD) for roads in the context of new/different drainage systems from a different perspective to that of the drainage engineer. This framework has historical antecedents discussed in a 2008 report contributed to by the University of Abertay, Dundee . The report explains how the Romans constructed roads in the UK with what is still recognised as durable technology. It is further mentioned that designers such as Macadam introduced modern roads and attempted to address the problems of drainage. As such, the structural integrity of roads have been protected and predicated on drainage systems being a major consideration in designers’ minds. As a result road developments have become multi­dimensional in function. The report explains that the traditional purpose and technicalities necessitating drainage integration in road construction is essentially to convey water as quickly as possible from the running surface, thus ensuring a clear safe path for road traffic, and to prevent water ingress to the road pavement structure preventing potential damage to the structure of the road. Traditional road surface water drainage techniques involved collecting runoff in roadside gullies, drainage kerbs or other collection devices which convey runoff to underground closed pipe systems. (See SUD for Roads, University of Abertay, Dundee contribution manual 2008). Diefenderfer, et al. (2002) in Onoyan­Usina, et al (2013) explain that the rate of road deterioration increases if the water content of the granular material increases as that in rigid pavements (i.e., concrete/impermeable surfaces). Thus, temperature gradients across the concrete slab can cause structural defects. Onayan­Usina et al (2013) highlight poor execution of construction jobs, poor maintenance, non­ compliance to planning requirements, and lackadaisical attitudes of residents within the context of drainage systems, as major factors 4
responsible for unsustainable road conditions. These two physical infrastructure categories are treated more or less in mutually exclusive manners
Figure 1: Typical Situation on some Lagos (Nigeria) roads after rain (Photo Credit. Lawal, 2011).
and as independent systems in such regions. In fact, a survey of literature reveals that in the analyses of both road and drainage infrastructure focusing on developing countries, these two variables are quite commonly ‘individualized’, as opposed to discourses in advanced nations, which more or less naturally incorporate the two, as one concept. The feasibility of this ‘individualization’ in underdeveloped nations lie in the fact that drainages could actually be efficient on inefficient roads (either poorly constructed, or not even tarred at all) creating permeability features in the roads. Essentially both infrastructure categories should ideally be simultaneously planned based on an integrated development approach. 3. STUDY STRUCTURE
This study largely adopts the use of published work in achieving the main objective of study. It focuses on studies carried out in developing countries. The focus on these regions is due to their characteristics and approach in urban infrastructure development of roads and drainages, as specified in the second section of this paper. Relevant documented scientific evidences sourced from various scientific literature e.g from journals, technical reports and papers from conference proceedings are reported and reviewed as secondary data. This is on order to investigate on how the theoretical concept under discussion actually plays out in reality and vice versa.
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4. REVIEW OF PUBLISHED RESEARCH ON ROAD AND DRAINAGE VARIABLES This section reports various researches in which road and drainage variables have been treated independently in statistical analyses. As mentioned in the previous section, it covers only researches carried out in developing nations. It would have been ideal to have been able to review more studies within this context, however the topic is quite debatable, and scientific environmental valuation of physical infrastructure is still yet to gain the attention it deserves in several underdeveloped nations.
Chandrasekhar (2005) studied the condition of neighbourhood facilities in different informal settlements in India. The survey essentially looked at the impact of government intervention and general conditions in the study area. Within the scope of ‘roads’ and ‘drainage’, a record of 52.7% and 46.6% respectively, was reported ­ relating to improvement in ‘government notified’ areas. In the ‘non­
notified’ areas, for roads there were recorded figures of 21.1% and 22.5%. These figures are associated with perceived performance improvements with the two categories of infrastructure respectively. In other assessment representations, the two infrastructure categories performed similarly. However, it would have been ideal for the author to have studied the statistical relationship between the two variables more scientifically. The study therefore doesn’t give adequate insight in this regard, though inferences can be made from the results.
Otegbulu and Adewunmi (2009), sought to determine the sustainability of housing development within the context of neighbourhood infrastructure provision. The study also set out to examine the level of averting cost and substitutes that households within the study area resort to. This was carried out using an environmental valuation technique. It was found that infrastructure provision is not sustainable in the study areas, based on their deplorable conditions, and in consequence households are willing to pay for its improvement (Willingness­to­
pay survey). Based on a contingent valuation approach, it was found that Poor drainage and road conditions were common failures occurring simultaneously and reciprocally. The authors report that places would get flooded after heavy rainfalls due to blocked drainage facilities. This was found to affect road sustainability. In a simple statistic, most drainage facilities in the study areas fell under the ‘Bad’ category. For Roads, similar results were recorded where degenerated road conditions (roads filled with potholes) accounted for 43.2% and 42.31% respectively in two neighbourhoods under study. While for ‘bad’ drainages, values derived supporting the facts were 87.9% and 65%. These represent the highest and second highest corresponding frequencies in both categories respectively. Whilst there is a disproportional relationship between the values attributed to roads and drainages, it can be seen that the relationships move in the same direction in the two study areas.
Famuyiwa and Otegbulu (2012) set out primarily to investigate the influence of water infrastructure on property prices. In identifying key significant variables, road and drainage infrastructure as individual variables were subjected to analysis in a hedonic regression model. Values derived from the estimates as contributory factors to property prices were 0.467 and 0.061 respectively. These two figures derived do not show any association at face value. However, no tests were carried 6
out to ensure reliability of the model; hence autocorrelation of these two infrastructure classes cannot be refuted or accepted. This factor alone may over estimate or underestimate the significance of other significant variables included in the model. In Famuyiwa and Babawale’s study (2014), the relationship and pricing effects of physical infrastructure on house rents using the hedonic technique was sought. Three models, namely the Linear, Log­Log and Log­Linear were used in testing this. The coefficient values derived from all three models for ‘Roads’ and ‘Drainage’ were put at 495362.52 & 308860.3, 0.161702 & 0.043420, and 0.148769 and 0.086760 respectively. The White’s heteroscedacity test was carried out to ensure the model can be relied on, and free from multicollinearity and heteroscedacity problems. ‘Road’ and ‘drainage’ variables seemed to be free from auto correlation and other possible model defects. The values also were not necessarily at par. As mentioned above, the environment valuation and pricing of physical infrastructure is relatively at its infancy in Nigeria, hence the limited availability of relevant literature. Several studies though, have been carried out on infrastructure sustainability and regional environmental features, the weightings in pricing of physical infrastructure in environmental valuation, are hardly the focus of many studies.
5. CONCLUSION
This study set out to investigate the theoretical relationship and behaviour of road and drainage infrastructure The conventional road construction and development strategies used in advanced nations are reflected in literature as seen in previous sections of this paper. This inextricably interwoven concept in urban infrastructure planning has been buttressed in scientific discourses, which explain that urban drainage systems are intricate interactions of the urban landscape to include buildings, roads, public sewers, private sewers and watercourses. (See 2008 report contributed to by the University of Abertay, Dundee). In developing countries, this concept helps ensure the attainment of sustainability, where recommended ideals of road development construction are contravened or simply ignored. From the technical and industry based perspective, this is somewhat reflected in scientific analyses as can be seen in some literature, and technical reports. However, the scientific relationship between road and drainage infrastructure of developing countries in statistical analyses can be unpredictable across board as seen in the survey of studies above. The mere fact that they are treated individually in such research reflects a ‘violation’ of ideal and recommended construction practice. This therefore makes it expedient for researchers to be more conscious of this, and check for autocorrelation or multi collinearity in models. A pilot study should be carried out first, when including them in statistical analyses. This practice will help validate findings of such research as well as help with preventing the occurrence of the possibility of distorted values of other infrastructure variables in models. This concept is not necessarily limited to road and drainage infrastructure 7
alone and similarly can be extended to environmental valuation techniques such as the contingent valuation and particularly hedonic pricing techniques.
REFERENCES
1. Chandrasekhar. S. (2005). Growth of Slums, Availability of Infrastructure and Demographic Outcomes in Slums: Evidence from India. Being a paper presented at the Population Association of America, 2005, Annual Meeting, Philadelphia, USA. 2. Famuyiwa, F. and Babawale, G.K. (2014). Hedonic Values of Physical Infrastructure in House Rentals. Journal of Facilities Management 12(3) pp. 211 – 230. 3. Famuyiwa, F. and Otegbulu, A.C. (2012). An evaluation of pipe borne water infrastructure in property prices: a contingent valuation approach. Elixir Infrastructure Mgmt. 51 (2012) 11034­11038.
4. Ksaibati, Khaled and Kolkman, Laycee L. (2005) Highway Drainage Systems and Design. The Handbook of Highway Engineering. Ed. T.W. Fwa. CRC Press.
5. Lawal, J. (2011). Lagos floods: Is Lagos going under? Bella Naija. Retrieved from http://www.bellanaija.com/2011/07/18/lagos­floods­is­lagos­going­under/ on the 25th of March, 2015.
6. Onoyan­Usina, Lazhi, Y.L. and Itomi­Ushi, D.L. (2013). Bad Drainage and Its Effects on Road Pavement Conditions in Nigeria. Civil and Environmental Research 3(10). ISSN 2224­5790 (Paper) ISSN 2225­0514 (Online) 7. Otegbulu, A.C. and Adewunmi, Y. (2009). Evaluating the sustainability of urban housing development in Nigeria through innovative infrastructure management. International Journal of Housing markets and Analysis.2(4). Pp. 334­346. DOI 10.1108/17538270910992782
8. State of Queensland Department of Transport and Mainroads (2010). Road Drainage Manual: A guide to the Planning, Design, Operation and Maintenance of Road Drainage Infrastructure Queensland Department of Transport and Main Roads, Brisbane, Australia.
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