I'm using this query to get all the lat and lon coordinates on a way from planet_osm_line: select st_astext(st_transform(way, 4326)) from planet_osm_line where osm_id = 482283890; The result is: LINESTRING(11.6168586 46.5434487002502,11.6168345 46.5431350002503,11.6167899 46.5429099002503,11.6172158 46.5425886002504,11.6176661 46.5424470002504,11.6180585 46.5424763002504,11.6181788 46.5425033002504,11.618848 46.5427728002503,11.6193672 46.5429585002503,11.6204657 46.5429528002503,11.6214048 46.5432146002503,11.6222983 46.5436187002502,11.6224615 46.5436944002502) What I see are the lon and lat coordinates for every node constructing the line, but the lat seems to contain extra information (last 6 digits, ie 002502). What is this information and how can I seperate it from the lat coordinate? asked 07 Feb, 12:15 Ruud Brandsma 
These are floating point represenation errors (from the conversion from lat/lon to mercator coordinates during import, and back in your query); they are not useful data. You can accomplish a rounding with
answered 07 Feb, 12:28 Frederik Ramm ♦ Thanks for your reply. Why are these floating point representation errors only occur on the latitude (precision of 13 digits) and not on the longitude (precision always 7 digits)?
(07 Feb, 12:39)
Ruud Brandsma
This is down to the formula used to compute the spherical mercator projection; computing the latitude value requires trigonometric functions, whereas computing the longitude is just simple multiplication:
You could largely avoid this issue if you used the l (the letter L) flag on osm2pgsql import, this would then refrain from projecting coordinates in the first place and make your
(07 Feb, 12:45)
Frederik Ramm ♦
