Nowadays the only safe option to reduce emissions during the daily traffic is to leave the car at home.
Recently a research by the European Commision has shown that driving at low speed is certainly safer and more respectful to the environment: this is based on the assumption that driving slower takes less fuel and produces fewer emissions.
However, this may be true on long distance trips, but some simulations showed that driving at low speeds in urban areas actually increases emissions.
An effective way to improve fuel economy in the short term is to aim at a change in driver behaviour and promote an environmen- tally friendly driving style.
Environmentally friendly driving includes different behavioural aspects to obtain a more fuel-efficient driving, one of them implying a selective use of gears.
By shifting gear early one can avoid high engine speeds and herefore achieve a reduction of emissions and fuel consumption.
In their studies, scientists combined the results of two different models trying to understand more about the phenomenon, anyway neither method is perfect.
The first one is based on a sophisticated approach to “microscopic”, checking second by second speed driving gear changes (the model VeTESS, developed by the EU project DECADE1).
The second method is just based on average speeds in different european countries (using a model Cover/MEET).
The data were recorded while cars were driven into the cities of Mol in Belgium and Barcelona, Spain.
Unfortunately both of two approaches are not perfect and it always depends on the type of car.