Emissions from the transport sector represent the fastest growing source of greenhouse gas emissions. There is little prospect that this situation will be resolved with a single technological fix. As developing nations quickly move to catch up with the motorisation levels of developed nations, the sheer number of private vehicles on the roadways will overwhelm any advances made by cleaner fuels. By the year 2030, there is projected to be more vehicles in the developing world than in developed nations. However, most developing cities today still have the basis for a more sustainable future. Public transport and non-motorised transport (walking and cycling) still command a dominant share of travel in developing cities. Thus, a key objective for local and international initiatives is to preserve existing mode shares. Unfortunately, most investment in reducing transport emissions relies exclusively upon achieving costly reductions only through fuel and propulsion system technologies.
Bogotá (Colombia) represents one of the best examples of a city that has developed a package of complementary measures to substantially reduce vehicle emissions and congestion. Bogotá’s implementation of a high-quality bus rapid transit (BRT) system, bicycle infrastructure, pedestrian improvements, car-free events, and auto restriction measures all have contributed to an urban transformation in a period of just a few years. Initial projections of greenhouse gas reductions during the first 30 years of the BRT system’s operation indicate reductions of approximately 14.6 million metric tons of CO2 equivalents.
This research presents a framework for evaluating the greenhouse gas emission reductions in the transport sector. This framework highlights three principal areas of emission reduction potential: 1.) Mode share (behaviour); 2.) Distance travelled (land-use/design); and 3.) Fuel efficiency (technology). Only by addressing all three components an optimum transport energy path can be achieved
