http://www.azstarnet.com/metro/290334
It seems there is a group of locals who want to keep the metric signs on I-19.
Excerpt from the article:
"These signs that were installed some 30 years ago contribute to the history of
the area when conversion to the metric system was being considered," wrote Stan
Riddle, president of the Green Valley Community Coordinating Council.
"The residents in the Greater Green Valley area find them a unique point of
conversation with both friends and visitors and the vast majority of residents
have no objection to them," the letter says.
The letter says directions are usually given based on exit number and travel
time, but the word "metric" doesn't enter the conversation.
Jerry