sql - Join intersecting lines with PostGIS

This is something that I'm almost ashamed to ask but I can't seem to get it to work for the life of me.

I have a road layer with segments, each segment has a Road ID and a segment type.

I would like to join all the segments together, for each Road ID into one linestring but only when they are the same type and are touching (all the lines are snaped together).

Road ID - Type

   1       L
   1       L
   1       T
   1       L

Answer

Seems this works

SELECT a."Road_ID",a."Road_Type", ST_LineMerge(ST_Collect(a.the_geom))
FROM "RoadCentreLines" as a 
LEFT JOIN "RoadCentreLines" as b ON 
ST_Touches(a.the_geom,b.the_geom) 

    AND a."Road_Type" = b."Road_Type" 
    AND a."Road_ID" = b."Road_ID"
GROUP BY ST_Touches(a.the_geom,b.the_geom), a."Road_Type", a."Road_ID"