Why do roads look wet on hot days?

Why do roads look wet on hot days?

Generally, the light rays from the sun travel towards the earth after suffering the atmosphere refraction, but on a hot day the roads heat up the air to a very high temperature  due to which the air right above the roads becomes less dense. Thus, the light rays on reaching the ground suffer further refraction, as a result of which, our brain senses that the light has reached us straight through the atmosphere and we see the image of sky on the ground. Hence the roads appear wet on hot days.

posed by vikash yadav