What is the precision of traceroute and ping location reports?
The IP to location mapping is based on the GeoLite2 City database.
Precision information for GeoIP2 City is available here: https://www.maxmind.com/en/geoip2-city-database-accuracy. The error is almost never smaller than 5km so the results have to be taken as a rough estimate only.
In certain cases, the location information corresponds to the company headquarters rather than the actual server location. For instance, for google.com the Californian Mountain View location is always returned even though the actual server is most probably located at a completely different place, depending on where the query was performed from.