The line graph illustrates the amount of nitrogen oxide is released by four particular vehicles. Overall, buses, followed closely by lorries, dominate to the production of nitrogen oxide, the reverse is true for diesel cars. It is, also, clear that petrol and diesel cars exhibit relatively stable emission levels across all speeds.
The figure of nitrogen oxide emission for buses and lorries are sensitive to their speed. Buses initially emit over 40 g/km of nitrogen oxide at 10kph. The figure decreases steadily as the speed increases, reaching the lowest at about 26 g/km at 60kpm. However beyond that spot, trade commenced to grow drastically, peaking the highest at around 43 g/km at the highest speed 130kph. Furthermore, lorries show resembled patterns, starting with approximately 33 g/km, dropping to about 18 g/km at 90kph, climbing up 25 g/km at ultimate velocity.
As for, petrol and diesel cars represent much lower emissions throughout. Petrol vehicles emit roughly 10 g/km consistently across all speeds, with negligible variations. Diesel cars follow a similar trend , yet at even lower levels, with emissions fluctuating around 5 g/km regardless of speed.