Impact Assessment of Causes of Vehicular Traffic Congestion on Urban Roads in Nigeria

This paper presents the result of impact assessment of causes of Vehicular traffic congestion on urban roads in Nigeria. The first phase of this research resulted in the identification of 49 causes of vehicular traffic congestion, which were subjectively grouped into five categories, namely: Societal Related Factors, Construction Related Factors, Design Related Factors, Government Related Factors and Natural Factors. In the second phase, questionnaires were developed based on the identified factors and distributed to a randomly selected sample of 30 Contractors, 25 Consultants and 34 FRSC personnel. The respondents were requested in the questionnaire to indicate the severity level of the impact of each of the 49 identified factors based on their personal judgment. The relative severity of the impact of each factor on vehicular traffic congestion was then assessed and ranked based on severity index by the Contractors, Consultants and FRSC personnel. The Contractors rated 28 factors as having “Highly Severe impact”, 14 as having “Moderately Severe impact”, and seven as having “Slightly Severe impact”, the Consultants evaluated 21 factors as having “Highly Severe impact”, 21 as having “Moderately Severe impact” and seven as having “Slightly Severe impact”, while the FRSC personnel evaluated 22 factors as having “Highly Severe impact”, 19 as having “Moderately Severe impact” and eight as having “Slightly Severe impact” respectively. The degree of agreement in the ranking of the three groups of respondents was tested using the Spearman Rho's rank correlation coefficient formula. The results show that Contractors, Consultants and FRSC personnel generally agreed on the severity ranking of the causes of Vehicular traffic congestion on urban roads in Nigeria.