Answer: courtesy and manners.
Explanation:
If a taxi driver opens, the door for his customer, that is an example of outmost courtesy and manners.
It is among the basic etiquette to open a door for a customer, mostly women. It builds a rapport for the driver and lightens the mood of the customer.
It can also be an example of professionalism
It is a sign that the taxi driver is showing respect and is acting professional towards his job.