The problem at hand is that a proposed trail has been drawn in order to provide services for the public. This example could apply to road construction or even finding sites for commercial properties for the purpose of provisioning services.
First, unzip the trail_census.zip file, then perform a quick data load using the following commands from the unzipped folder:
shp2pgsql -s 3734 -d -i -I -W LATIN1 -g the_geom census chp02.trail_census | psql -U me -d postgis_cookbook shp2pgsql -s 3734 -d -i -I -W LATIN1 -g the_geom trail_alignment_proposed_buffer chp02.trail_buffer | psql -U me -d postgis_cookbook shp2pgsql -s 3734 -d -i -I -W LATIN1 -g the_geom trail_alignment_proposed chp02.trail_alignment_prop | psql -U me -d postgis_cookbook ...