In November 2009 the opening of the A4 in Knonaueramt between the branches of Zurich West is planned, at Blegi Cham.

The tunnel opened in 2005, is again shown as Flüelen Bypass Highway; yet the connection to the A2, however, remained as a non-main road intersection.

On 20 October 2006, the Swiss Federal Department of Environment, Transport, Energy and Communications (DETEC) started a project to strengthen the implementation of the two-lane national highway between Flurlingen and Andelfingen, officially approved as a four-lane mini-freeway.

From Schaffhausen south, the A4 will create a 1,138-metre (3,734 ft) long tunnel with a slope of 4.5 percent, through the Galgenbuck Klettgau to the main road into the 13th link with the A4 intersections.

Since this law concerns the transformation of a motorway connection, the federal government provides, under the new system of financial and division of tasks between the Confederation and the cantons, the full costs of approximately CHF 175 million.

Ending on barges crossing the national highway 4 is obtained on the German side of any road performance, the transit traffic in the direction of Stuttgart, called on the cantonal main road 15 (J15), carried out through the border crossing Thayngen, and then removed from the German federal highway 34, which for Bundesautobahn 81 leads.

The Canton of Schaffhausen agreed in principle to the project, with the opinion on 15 September 2008 unanimously (69: 0 votes) adopted.