I-1 road (Bulgaria)

The I-1 road is a major road in Bulgaria, part of the Bulgarian road network. It runs generally in a north-south direction, connecting the capital Sofia to the border with North Macedonia at the Gyueshevo border checkpoint, and further north, to the border with Serbia at the Kalotina border checkpoint, continuing onwards towards Vidin and the Danube Bridge 2.

The I-1 is part of European route E79, which continues southward through North Macedonia and Greece. The section between Sofia and the North Macedonian border is an important transport corridor for traffic between Bulgaria and its southwestern neighbors. The segment between Sofia and Botevgrad forms part of the European route E772.

Significant portions of the I-1 are being upgraded to motorway standards as part of the Struma motorway (A3) project in the south and the Europe motorway (A6) project in the west. The upgrades aim to improve traffic flow and safety along this busy route. The remaining segments are generally two-lane roads, undergoing continuous maintenance and reconstruction to improve their condition. The road passes through or near major cities and towns including Sofia, Pernik, Dupnitsa, Kyustendil, and Vidin.