local $_ = join "\n", @trip;
printf "%15s to %-15s\n", $1, $2  while /^(.*)\n(?=(.*))/gm;
##</code><code>##

my $test = "Chicago
Saint Looey
Joplin
OKC
Amarillo
Gallup
Flagstaff
Winona
Kingman
Barstow
San Bernandino
LA" ;

if ( $test =~ /^(.*)\n(?=(.*))/gm ) {
	printf "%15s to %-15s\n", $1, $2 ;
}
__END__ 
        Chicago to Saint Looey