You are right.

Also “The Authority may designate different maximum speeds … during periods of adverse atmospheric or weather conditions. Maximum speeds … during any period of adverse atmospheric or weather conditions shall be in accordance with signs displayed for such zones. All regulatory and zoning signs displayed on the Turnpike shall be obeyed.”

and also

“Motor vehicles shall not be driven in excess of the mechanical limits of vehicles or tires. If traffic, weather, pavement or other conditions render the maximum allowable speed hazardous, the speed of motor vehicles shall be reduced consistent with such conditions.”