Doodling a layout plan for an OO layout for a 9 X 12 space to answer a query on this forum I found only 6 X 2 for storage sidings at right angles to a 8 X 2 wall section.   As half this wall would be taken up with apprach trackwork to hiden sidings I doodled a Traverser and realised  with no 2 or 3 radius set track I could get 50mm track spacing with the Traverser only moving approx 25mm per road by airing the approach tracks 1 + 3 and 2 + 4.   The track would converge on the traverser edge