Switzerland in east west direction. Similarly to it the a2
the north with the south. The A1 got its name at the end of
and is to a large extent congruent with
(national route) - exceptions form the regions Zurich (N1b/N1c, late N20) and Geneva (N1a).
The A1 connects the Geneva lain
in the northeast. It is today continuous implemented as direction-separate motorway with at least two traces and Pannenstreifen per direction of travel. The A1 is the life vein of the Swiss central country and connects all important marketing areas.
The motorway feeders (A1a, A1H, A1L and A1.1) are implemented usually as direction-separate motorway, do not belong however not compellingly to the national route net.
In the region Zurich is particularly close traffic on the A1, it forms regularly
. In order approximately to prevent the total collapse in commuter traffic around Zurich and particularly in Zurich north to unlock the drivers to rush hours - against all otherwise dominant regulations - continue closely with which the capacity of the A1 overloaded anyway can be better used. Since traffic constantly increases considered whether on sections of the Pannenstreifen as the fourth trace is to be used.
Notorious was in former times
, since it is there on the section, which is used together by the motorways 1 and 3 (Birrfeld Limmattalerkreuz). The motorway possesses in this section three driving strips plus Pannenstreifen per direction, the two old tunnel tubes against it was only ever zweispurig (without Pannenstreifen) laid out. With the building of a third dreispurigen tunnel tube for the driving direction Berne and the two old tunnel tubes, which now both lead traffic toward Zurich, this bottle neck could be eliminated. Thus the back-up was shifted however to
the Gubristtunnel, which suffers from the same problem. The Gubrist was built in the context of the north by-pass (N1c/N20) and only zweispurig implemented, must master the traffic of the motorways 1 and 4 however today. At present still planning runs, in order to carry out a third dreispurige tube also here.