I still use "One" quite a lot in writing (especially forums) when I need to discuss your personal opinion without implying that I'm speaking for the other parties in the conversation. i.e.
"You often see cars speeding along this road" <- perfectly valid and the context can be taken from the way it is delivered in speach, but could be misread to imply that the writer thinks the person they are addressing sees the cars.
"One often sees cars speeding along this road" <- unambiguous.
"You often see cars speeding along this road" <- perfectly valid and the context can be taken from the way it is delivered in speach, but could be misread to imply that the writer thinks the person they are addressing sees the cars.
"One often sees cars speeding along this road" <- unambiguous.