On 29 November 2017 contractor Implenia broke through on the 2.7km-long Bözberg tunnel which runs between its southern portal at Schinznach-Dorf to a northern one near to Effingen in Switzerland.

On 29 November 2017 contractor Implenia broke through on the 2.7km-long Bözberg tunnel which runs between its southern portal at Schinznach-Dorf to a northern one near to Effingen in Switzerland.