select
	st_distance(g.the_geom , st.the_geom) as distance_meters,
	st_line_locate_point(st_linemerge(st.the_geom), g.the_geom) as fractions_2d_length,
	st_m( st_line_interpolate_point(st.the_geom, st_line_locate_point(st.the_geom, g.the_geom))) as measured,
	st.*, g.*
from
	streets_centerlines st,
	fred_city_o6_da_centroids g
where
	--g.gid =
	--AND
	st.the_geom && ST_expand(g.the_geom, 2000)
order by distance_meters

-- ERROR:  line_locate_point: 1st arg isnt a line