History
"Interstate 19 is unique amongst US Interstates, because signed
distances are given in meters (hundreds or thousands as
distance-to-exit indications) or kilometers (as
distance-to-destination indications), and not miles. Speed limit
signs give speeds in miles-per-hour, however. According to the
Arizona Department of Transportation (ADOT), metric signage was
originally placed because of the "metric system push" in the United
States at the time of the original construction of the
highway."
Wikipedia
Terrain
o Parking within 0-ft
o Caution needed on/near cattle guard
o May require squatting or kneeling