This traceroute tool tries to find out in various ways where each hop along the path is located and visualizes that on a google map. This is done by querring the DNS for a "LOC" (RFC 1876) entry, if that fails, a internal database table is used to determine the location via a regular expression on the hostname. When no entry is found, a whois query on the IP-address is made to determine the location (City Name, Country) and the result is then translated to coordinates with the help of a local database. If even that fails, it falls back to use NetGeo.

Please have a look at the missing routers