The New Austrian Tunnelling method (NATM) was developed between 1957 and 1965 in Austria. It was given its name in Salzburg in 1962 to distinguish it from old Austrian tunnelling approach. The main contributors to the development of NATM were Ladislaus von Rabcewicz, Leopold Müller and Franz Pacher. The main idea is to use the geological stress of the surrounding rock mass to stabilize the tunnel itself.

The NATM integrates the principles of the behaviour of rock masses under load and monitoring the performance of underground construction during construction. The NATM is not a set of specific excavation and support techniques and has often been referred to as a "design as you go" approach to tunnelling providing an optimized support based on observed ground conditions but more correctly it is a "design as you monitor" approach based on observed convergence and divergence in the lining as well as mapping of prevailing rock conditions.