The construction of the new Axenstrasse along National Road N4 is one of Switzerland’s most significant road construction projects. It’s no wonder, as this road is one of the most important routes on the Swiss north-south transit axis, a status it has held for over 150 years.
The new Axenstrasse replaces the existing section of National Road N4 along Lake Uri. The project significantly improves road safety between the central Swiss cantons of Schwyz and Uri. Additionally, the small village of Sisikon, with a population of 380, will be sustainably relieved from traffic.
The centerpiece of this project is the 2,8-kilometer-long Morschacher Tunnel and the 4,4-kilometer-long Sisikoner Tunnel. Both structures will protect the road from external dangers like rockfalls and debris flows. In the past, such natural events have frequently led to the closure of the national road.
Considering that construction work is continuously exposed to the risk of rockfalls for an extended period, an early warning system has been implemented. This system records rainfall, wind and gusts of wind. When predefined limits are exceeded, an SMS warning is sent, leading to the closure of the relevant construction site areas.
A positive side effect on the New Axenstrasse project is that a portion of the excavation material, together with material from the Second Gotthard Road Tunnel, is used for the continuation of the “lakefill” flagship project on the southern shore of Lake Uri. This creates new shallow water zones that provide a habitat for flora and fauna. The “lakefill” project contributes to biodiversity and continues a multi-generational project that began 1985 to enrich the ecosystem of the Reuss Delta sustainably.