Explain why the pressure inside a tyre increases when a vehicle moves for a long period of time.

(N/A) When a vehicle moves for a long period of time,the tyre becomes warm due to friction between the tyre and the road surface.
As a result,the temperature of the air trapped inside the tyre increases.
Since the volume of the tyre remains approximately constant,according to Gay-Lussac's Law ($P \propto T$ at constant volume),an increase in temperature leads to a proportional increase in the pressure of the air inside the tyre.