I thought I should go left, but in the Underground, the automated announcement tells everyone to stand to the right on the escalators so that people walking up or down can pass on the left, just like on our Metro. (Though folks seem better trained in London--maybe there are more announcements. In D.C. people--and yes, we like to blame the tourists--all too often stand two abreast and clog things up.) Sometimes in navigating our way between Underground lines or between the Underground and a train station, signs told us to keep left--but other times they told us to keep right.
On the flight over, the Scotsman sitting next to me said he'd rented a car to tour some of the D.C. suburbs and was very nervous driving on the wrong side of the road. LOL. I hadn't focused on the fact that it would be just as disorienting for someone from Great Britain to get used to our cars and driving pattern as it is for us to adjust to theirs.
And Mr. M and I decided early on that there was no way we were renting a car. Obviously some people can manage it, but we were pretty certain we weren't two of them. We found crossing the street challenge enough.