The Strand Underpass is of note, being converted from a former tram
subway and being tiny compared to pretty much any other road tunnel you
will ever go through. I don't know if buses still go through it in the
rush hour. Occasionally the northern end of the tram subway is open for
art events, allowing pedestrian access to the former platforms with old
roundels, but I doubt if the day of your trip will be such a day. The
tram tracks leading down from the Theobalds Road junction are of minor
interest. I believe that the small square archway in Holloway Road
almost opposite Witley Road is the only other place that you can still
see abandoned tram tracks, see
https://www.flickr.com/photos/warsaw...57626135089492