Traveling by car from Erbil to Mosul takes about 90 minutes. You must have a valid Federal Iraq visa, as a Kurdistan regional visa alone does not permit entry past federal checkpoints. Along the route, you will pass the Khazer checkpoint where federal soldiers inspect passports, visas, and vehicle paperwork. Keep your passport and printed visa confirmation easily accessible. Inspections can range from five to thirty minutes depending on shifts and traffic lines. For more: Mosul Travel Guide: Visiting the Old City, Safety, and What Is Open