Drivers across Turkey are asking when the mandatory winter tire rule begins, and the timing now has a firmer shape. The Transport and Infrastructure Ministry has settled the calendar for the 2026-2027 season under its existing regulation. The obligation applies to commercial vehicles, which must run on winter tires during the cold-weather window set by the ministry. Operators who ignore the requirement face roadside checks and fines once the period starts. Timing matters because eastern provinces hit wintry conditions weeks before the Aegean and Mediterranean coasts do. The technical reason behind the rule is simple: summer rubber hardens in low temperatures and loses grip on ice and snow. Motorists running commercial vehicles are advised to book the changeover early instead of waiting for the first storm.