SELECT CASE
	WHEN R.seq = 0 THEN geom
	WHEN ST_DWithin(ST_StartPoint(geom),ST_EndPoint(LAG(R.geom,1) over (ORDER BY R.seq)),1) THEN R.geom
	WHEN ST_DWithin(ST_StartPoint(geom),ST_StartPoint(LAG(R.geom,1) over (ORDER BY R.seq)),1) AND 		ST_DWithin(ST_EndPoint(LAG(R.geom,1) over (ORDER BY R.seq)),ST_StartPoint(LAG(geom,2) over (ORDER BY R.seq)),1) THEN R.geom
	WHEN ST_DWithin(ST_StartPoint(geom),ST_StartPoint(LAG(R.geom,1) over (ORDER BY R.seq)),1) AND ST_DWithin(ST_EndPoint(LAG(R.geom,1) over (ORDER BY R.seq)),ST_EndPoint(LAG(geom,2) over (ORDER BY R.seq)),1) THEN R.geom
	ELSE R.reverse
	END AS geom,
	R.seq
FROM route R