RATP Bus Fleet and Network Emissions
This paper exposes how the Parisian public transport company had characterised emissions of the complete fleet (4.000 buses) in the driving conditions in the urban area of Paris.
Buses emissions are so far measured via a vehicle test bench. Nevertheless, this costly and complexes measurements are done in a particular configuration, at a precise period which are not representative of the complete fleet and all the driving configurations that can be met in an urban environment.
The work is done in two phases.
The first one consists in analysing the fleet in order to determine a statistic representation of it. Measurements of regulated pollutants are done with a static instrumentation on about 400 buses (approximately 10% of the fleet in use) as a function of the type of vehicle, fuel, age, mileage, presence or not of a post-treatment, of air cooling…
In the second phase, with the aim to characterise the geographic distribution of emissions, measurements are done on real driving conditions with a dynamic system. This experimentation done with one bus will make possible the association of pollutant emissions with particular motor parameters. Previous works had defined the driving conditions in the RATP bus network, described in four driving cycles. The association of these results allows calculating regulated pollutant emissions in all driving conditions over the whole network.
Then, the association of results obtained during these two phases leads to a complete characterisation of pollutant emissions of an important bus fleet in a large urban scale.