SELECT id, ST_Buffer ((geom), 0.0001,'endcap=round join=round') as geom
FROM roads_split;

SELECT a.id,
  ST_LineMerge(
    ST_Difference(ST_ExteriorRing(a.geom), b.geom)
  ) geom
FROM roads_union_byf a;
LEFT JOIN roads_union_byf b ON (ST_Intersects(a.geom, b.geom)
AND a.id < b.id);

create table roads_cut_poly_l as
SELECT id, ST_MakePolygon(ST_AddPoint(geom, ST_StartPoint(geom))) geom
FROM roads_cut_l;

create table roads_cut_r as
    SELECT  a.id,
      ST_LineMerge(
        ST_Difference(ST_ExteriorRing(a.geom), b.geom)
      ) geom
    FROM roads_union_byf a
    LEFT JOIN roads_union_byf b ON (ST_Intersects(a.geom, b.geom)
    AND a.id > b.id);

create table roads_cut_poly_r as
SELECT id, ST_MakePolygon(ST_AddPoint(geom, ST_StartPoint(geom))) geom
FROM roads_cut_r;

create table roads_union_split as
SELECT ST_Intersection(a.geom, b.geom) as geom
FROM roads_cut_poly_r a, roads_cut_poly_l b
WHERE ST_Intersects (a.geom, b.geom)
AND a.id=b.id;

create table roadsegment_pt_split1 AS
SELECT ST_LineInterpolatePoint (roadsegments_marge.ggeom, 0.1) as geom
FROM roadsegments_marge

create table roadsegment_part1 as
SELECT ST_MakeLine (geom) as geom
FROM roadsegments_pt_split;

create table roadsegment_part2 as
SELECT ST_MakeLine (geom) as geom
FROM roadsegment_pt_split2;

create table roadsegment_buffer_part1 as
SELECT ST_Buffer ((geom), 0.0001, 'endcap = flat join = round') as geom
FROM roadsegment_part1