Air pressure in a car tyre increases during driving. Explain.

(N/A) The volume of a car tyre is approximately fixed. During driving,the friction between the tyre and the road generates heat,which increases the temperature of the air inside the tyre. Since the volume $V$ remains constant,according to Gay-Lussac's Law,the pressure $P$ is directly proportional to the absolute temperature $T$ $(P \propto T)$. Therefore,as the temperature increases,the air pressure inside the tyre also increases.