Durham (Regional Municipality) v. Snowden, 2012 ONCJ 676 (CanLII)
http://canlii.ca/t/ftjsp[quote]52. The court therefore finds that while the orange and black temporary or advisory speed limit signs to be unenforceable. Given the white regulatory speed limit signs with black lettering which are enforceable were covered at the time of the alleged offence, the speed limit in the area legally reverted to a 50 km/h zone as defined under the Highway Traffic Act.[/quote]