Here's a good video explaining why its important to replace your tires when the tread is too worn
It seems like a lifetime ago now, but I actually got a patent back in my engineering days for an algorithm to detect aquaplaning as part of ABS systems.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-bool.html&r=7&f=G&l=50&co1=AND&d=PTXT&s1=abuelsamid&OS=abuelsamid&RS=abuelsamid?
