Something

gis=> select distinct on (p.way) p.osm_id, p.way as way,l.highway as int_tc_type
from planet_osm_point p
join planet_osm_line l
on ST_DWithin(p.way,l.way,0.1)
join (values ('tertiary',1),
             ('unclassified',2),
             ('residential',3),
             ('living_street',4),
             ('service',5)
) as v (type,prio)
on v.type=l.highway
where p.highway='turning_circle' and p.way && transform(setSRID('BOX3D(7.857107 48.111101, 7.860465 48.112841)'::box3d,4326),900913)
order by p.way,v.prio
;
  osm_id   |                        way                         | int_tc_type 
-----------+----------------------------------------------------+-------------
 181733072 | 010100002031BF0D0081DB450295B22A416D147E20EF5D5741 | residential
(1 row)


gis=> explain analyze select distinct on (p.way) p.osm_id, p.way as way,l.highway as int_tc_type
from planet_osm_point p
join planet_osm_line l
on ST_DWithin(p.way,l.way,0.1)
join (values ('tertiary',1),
             ('unclassified',2),
             ('residential',3),
             ('living_street',4),
             ('service',5)
) as v (type,prio)
on v.type=l.highway
where p.highway='turning_circle' and p.way && transform(setSRID('BOX3D(7.857107 48.111101, 7.860465 48.112841)'::box3d,4326),900913)
order by p.way,v.prio
;
                                                                                                                                             QUERY PLAN                                                                                                                                             
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Unique  (cost=1005.21..1005.22 rows=1 width=118) (actual time=8.796..8.800 rows=1 loops=1)
   ->  Sort  (cost=1005.21..1005.21 rows=1 width=118) (actual time=8.794..8.796 rows=2 loops=1)
         Sort Key: p.way, "*VALUES*".column2
         Sort Method:  quicksort  Memory: 25kB
         ->  Nested Loop  (cost=0.00..1005.20 rows=1 width=118) (actual time=1.377..8.774 rows=2 loops=1)
               Join Filter: (l.highway = "*VALUES*".column1)
               ->  Nested Loop  (cost=0.00..1005.07 rows=1 width=114) (actual time=1.349..8.736 rows=3 loops=1)
                     Join Filter: ((p.way && st_expand(l.way, 0.1::double precision)) AND (st_distance(p.way, l.way) < 0.1::double precision))
                     ->  Index Scan using new_point_index on planet_osm_point p  (cost=0.00..14.72 rows=1 width=104) (actual time=1.269..1.485 rows=1 loops=1)
                           Index Cond: (way && '010300002031BF0D000100000005000000AA72FA4C32B12A418EE39D81CB5D5741AA72FA4C32B12A4141304908145E5741A63022EC1DB42A4141304908145E5741A63022EC1DB42A418EE39D81CB5D5741AA72FA4C32B12A418EE39D81CB5D5741'::geometry)
                           Filter: ((way && '010300002031BF0D000100000005000000AA72FA4C32B12A418EE39D81CB5D5741AA72FA4C32B12A4141304908145E5741A63022EC1DB42A4141304908145E5741A63022EC1DB42A418EE39D81CB5D5741AA72FA4C32B12A418EE39D81CB5D5741'::geometry) AND (highway = 'turning_circle'::text))
                     ->  Index Scan using new_line_index on planet_osm_line l  (cost=0.00..984.48 rows=235 width=1249) (actual time=0.058..5.299 rows=41 loops=1)
                           Index Cond: (l.way && st_expand(p.way, 0.1::double precision))
                           Filter: (l.way && st_expand(p.way, 0.1::double precision))
               ->  Values Scan on "*VALUES*"  (cost=0.00..0.06 rows=5 width=36) (actual time=0.001..0.005 rows=5 loops=3)
 Total runtime: 8.909 ms
(16 rows)