The line graph illustrates the nitrogen oxide pollutions manufactired by different means of transport.
Overall, buses and lorries experienced some considerable changes, over the period. Nevertheless, 2 of this vehicles remained relatively stable, are petrol car and diesel car.
First of all, buses had a significant decrease until approximatelly 25 g/km. However, consequently, it escalated dramaticlly, and get even higher ,in comparison to beginning. Moreover, it is considered as the vehicle,which produces the most significant amount of this type of oxide emission. Additionally, lorries also experienced sharly drop,but it was for 40 kph longer than buses, with a sligth rise for nearly 7 g/km, from 17 to 25 nitrogen oxide emissions.
Althougth, there is some simularities between petrol and diesel cars, which are caused because of quiete simular stability in both of cases. Nonetheless,according to the diagram, they have for about 5 g/ km differences, during this period of time.
