Cost and benefits of clean technologies for bus rapid transit (BRT): Summary of results for Nairobi

Bus Rapid Transit (BRT) systems have been shown to be one of the biggest reducers of greenhouse gases emissions in cities of developing countries. The sustainability of BRT systems will however depend critically on the energy source, fuel type and quality, vehicle technology and the infrastructure available.

A cost benefit analysis (CBA) of different clean technology options for BRT buses, taking in account the local situation in each of the three SUSTRAN cities, was carried out. These included the existing and future energy sources (including regional sources); fuel type and quality; vehicle technology and infrastructure, available in each of the three cities of Nairobi, Kampala and Addis Ababa. The CBA also compares costs – in economic, environmental and social terms – with benefits. 

Key findings

• Based on preliminary assumptions about the future BRT system, the ICCT’s modeling of city-wide pollutant emissions, fuel consumption, health impacts, and time saved suggest that a BRT system in Nairobi will result in considerable overall benefits in the range of $42 to $51 million per year in 2035. Costs for vehicles and infrastructure range $23 to 29 million per year.
• Bus technology feasibility analysis identified multiple potential technologies for consideration in Nairobi’s BRT system: diesel, hybrid diesel-electric, and LPG buses for Phase I (2013-2020); and clean diesel (with exhaust aftertreatment devices), hybrid diesel-electric, LPG, and electric trolley buses for Phase II (2020-2030).
• Among the BRT bus technologies, the analysis revealed that the selection of any of the advanced technology choices – including the cleanest diesel conventional and hybrid-electric buses and trolley electric buses – will result in significant emissions reductions at modest additional cost over a Euro III diesel baseline bus. Several of these advanced technology choices result in significant fuel use and CO2 emissions reductions (in the range of 600,000 cumulative tons by 2035).