Is Oxford st One way or Two way?

Another London query!
Can anyone advise me whether it is possible to drive a Car from Marble Arch
along Oxford st to
roundabout at intersection of Old& City Rds, heading towards Hackney.

The route I would be expecting to drive would be Oxford St New Oxford St
Bloomsbury Way Thedobold Road Clerkenwell Rd Old St around
roundabout
Old St Hackney Road.

Or would it be easier to go:

Up Edgeware road to the (A501) ie Marylebone road Euston Road
Pentonville road
City Road left at roundabout Old St Hackney road.

I am aware Oxford St is in London congestion zone and A501 is not, this is
irrelevent to my situation.
Oxford St would be more direct for if it is possible. Even looking with
Google earth,
some areas of Oxford St. are hard to determine situation

regards
John H