When one drives a vehicle a lot with the window rolled down and thier arm resting on the edge of the door where the window is rolled down - that arm receives a lot more exposure to the sunlight than the other arm, resulting in that arm being more tanned than the other.
Because the occupation of a taxi driver requires a lot of driving, sometimes they get the "taxi driver's tan" effect.
Bob: Hey look at John in his tank top.
Joe: Wow, look at his arms, he sure has a taxi driver's tan.
Buy a
taxi driver's tan
mug!
