In Portugal lines before 1990 are built with a distance of 3,5m from center-to-center of track. The speed was limited at the time to up to 140km/h.
From 1990 onwards spacing is set at 4,0m up to 2010, and normally grouped in pairs when more than two tracks run alongside. (2+1; 2+2; 2+2+1; etc...)
The speed limit was now topped to 220km/h with EBICAB.
Starting from 2010 the spacing was updated to 4,5m in new lines, and the same grouping of pairs applies. 220khm/h is now applied with EBICAB and ERTMS.