Why do some elevated/ subway train operators wear gloves while operating a train?

Question

I've noticed that some of the operators wear gloves while operating their train, even in the summer. Some do not. What's the reason, either with or without gloves?

Answer 1

Could it be to prevent electric shock from static electricity built up on the metal control handles?

When the first Blue Pullmans were introduced on the Swansea to London Paddington route in the UK, the two drivers wore white gloves as part of their uniform. Needless to say, the gloves did not last  more than a few weeks.

Answer 2

is it cold ?

Answer 3

Keeps controls clean.

Drivers have duties which require them to work on the outside of the train, sometimes, and the amount of muck on the exterior of trains is unbelievable.

It makes it more pleasant for the next driver who gets on.