trancer96: Time for this to go. The puzzle never really worked as intended and the cache location kept getting compromised. Thanks to those to made the effort to come up and find this.
The cache has been removed.
For anyone still wondering how this was supposed to be solved it goes as follows:
Atomic City to Las Vegas: Take highway 26 and I15 (26+15=41)
Whatawhata to Whakamaru: Take highways 39, 3 and 30. 39-3-30=6
Großräschen to Ludwigsfelde: Take highways 96,13 and 10 (96+13+10=119)
Manchester to Boston: Highways 90 and 84 (90+84=174)
Martinborough to Lower Hutt: Highways 53 and 2 (53-2=51)
Malmesbury to Bridgwater: Take highways 429,4 and 5 (429-4-5=420)
Why are some subtracted? Those countries drives on the left. The added ones drive on the right. This is what hint 3 was about.
So the cache was at S41 06.119 E174 51.420.