Since 1964 the asphalt road-construction in Switzerland has experienced a remarkable upturn.

Up to 1990 around 14.000.000 m² asphalt pavements were built with Trinidad Natural Asphalt – more than 2/3 of this in asphalt concrete.

At the beginning of 1992 all TNA-asphalt concrete surfacings in the canton Aargau were recorded and an examination of the economic effectiveness was carried out.