Home / Saskatchewan / Questions / Rules of the Road Rules of the Road Report Tread 1.5 mm: A OK B Replace — below legal 1.6 mm C Ignore D Winter only Show Answer & Explanation Correct Answer: B. Replace — below legal 1.6 mm Replace safety. Previous Next More Rules of the Road Questions Ignition interlock after impaired conviction: Refusing breath sample: Worst SDR rating: Best Safe Driver Recognition rating: SDR affects: Often Missed All Saskatchewan Questions Smart Practice Mock Exam Road Signs Guide