Quick question...

[senojnitram]

OO gauge track. 4 parallel tracks, what is the measurement from outside of track one to the outside of track 4 please?

[4472]

Differs from straight to curves where you have to allow for overhang on passing coaches

[Flashbang]

Peco Setrack and Hornby track are all to 67mm track centre spacing.
3 x 67 = 201mm plus on straights add a minimum 15mm per outside. So 231mm over all. Note this is for straight tracks and allows little clearance each side

[senojnitram]

Ideal, thanks for the info