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University of Eldoret


Traffic congestion is a wasteful phenomenon to businesses, society, environment and the economy as a whole. Its effects include delayed travel times, reduced productivity and business opportunities, accidents, frustrations, stress and pollution. This study analyzed the economic impacts of traffic congestion and effectiveness of different decongestion measures in Nairobi city, Kenya. Identification of study variables relied on theories and principles from welfare economics, congestion management; stakeholder participation; measuring impacts of traffic congestion; and, Contingent Valuation Method (CVM). Data was collected through questionnaires administered to the city’s motorists, interviews with key informants, observations and secondary data sources. Descriptive statistics, mathematical computations and counterfactual analysis were used to analyze the data. Regression analysis was used to model the relationship between motorists’ Willingness-to-Pay (WTP) for traffic decongestion program and their socio-economic characteristics. Results showed that the city’s congestion is due to continuously increasing number of vehicles without effective corresponding long-term congestion management strategies. Its related wastages were estimated as Ksh 146.5 billion and Ksh 16.7 billion annually in terms of delays and wasted fuel respectively. CVM results showed an average monthly motorists’ WTP of Ksh 1387 totaling to Ksh 8.3 billion annually interpreted as the total value of some benefits of reducing congestion in the city. Regression results also showed that motorists’ income, cost of running cars, price of cars and their perceptions on Government’s role in infrastructural projects were statistically significant at 5% in explaining their WTP bids. Bypass roads were found to minimally have a 7.5% impact in curbing congestion. The expansion of Thika Road and Syokimau commuter train service was estimated to have saved motorists Ksh 80 billion and Ksh 117.03 billion annually, respectively in terms of delays and wasted fuel. Phasing out of 14-seater PSV per se is ineffective in alleviating congestion and has potential of crippling the city’s public transport. With an effective payment machinery, the WTP values show the potential of funding the expensive decongestion programs using Nairobi city’s own resources. Decongestion programs should entail amongst others redesigning of the city’s land use policy in relation to congestion management strategies and parking management policy; introduction of congestion pricing schemes; development of new and modification of road infrastructure; encouraging use of public transport through introduction of consultative BRT systems; improving traffic operations; and, establishing a single agency that shall manage and coordinate efforts on the problem instead of relying on numerous government institutions with disjointed roles. There is need to cascade such research in other growing towns within the county to share experiences and develop national statistics on the problem.