http://www.muellerworld.com/pcd0968/presidential_highway-13.html has a picture of one of the signs.
Somewhere in the middle of this stretch there's even a pair of flagpoles with the New Zealand and American flags flying from them.
I imagine they must have been somewhat disappointed when Al Gore didn't become president. However, that was over three years ago and they still haven't taken down the signs, so perhaps they're permanent.
"[In] New Zealand, there are two towns not very far apart with the names of Clinton and Gore. The towns had those names long before Americans ever heard of either man. The Kiwis named the road between the two towns the "Clinton-Gore Presidential Highway.
"Southland, the province where the highway is located, named the road in honor of President Clinton's visit to New Zealand for the Asia-Pacific Economic Cooperation Group meeting in 1999. Clinton was so impressed with the gesture that he requested a replica of the road sign for his presidential library in Little Rock, Ark."