Energy and environmental impact of the Abidjanese way of life (Côte D’ivoire): A case study of energy efficiency of transport modes

As part of the protection of the environment in general, and in the particular case of Abidjan which is threatened by pollution from exhaust fumes, a survey was conducted on the 7 modes of transport currently used by Abidjanese, estimated at nearly 4.4 million at the last census of Cote d’Ivoire [5], i.e. 19.4% of the Ivorian national population. The survey aims to determine the energy consumption to transport a passenger over one kilometre (p.km), according to the transport mode which are : Communal taxi, Intercommunal taxi, Taxi, Sotra Bus, Sotra Bus Boat, Personal car and Mini-bus commonly known as "Gbaka". The average consumption of all light vehicles is 11.0 lge/100 km (litres of petrol equivalent per 100 km), well above the limit set by the North American CAFE (Corporate Average Fuel Economy) regulations [9], which is set at 8.6 lge/100 km, and that of the EU, which is set at 5.6 lge/100 km [10]. This is partly due to the ageing of the light vehicle fleet in Cote d’Ivoire. In terms of energy consumption to transport one passenger over 1 kilometer (specific energy consumption), the Sotra Bus and the Gbaka are the most efficient transport modes, with 0.28 MJ/p.km and 0.43 MJ/p.km respectively. Within Sotra Bus, the Monbus service is the most efficient of all Abidjan’s transport modes with 0.20 MJ/p.km. In contrast, the Taxi and the Personal car are the least efficient, with 3.50 MJ/p.km and 2.27 MJ/p.km respectively. In terms of specific energy consumption, the Collective taxi (1.39 MJ/p.km) is 38.77% and 60.29% more efficient than the Personal car and the Taxi respectively. Specifically, the Intercommunal taxi (0.84 MJ/p.km) is 63.00% and 76.00% more efficient than the Personal car and the Taxi respectively. This relative efficiency of the Collective taxi results from its mode of operation which maximises its occupancy rate.