On 14 August 2018 a viaduct in Genoa collapsed killing 43 people.
Switzerland’s national road network, which covers 1,840 km, contains 4,548 road bridges and viaducts. The highest, the Mentue bridge, is 113 m above the ground, and the longest, the Yverdon viaduct, is 3,155 m long. Both are in the canton of Vaud.
Another prominent flyover is the one passing near the Chateaux de Chillon near Montreux, a structure dating from the same era as the one that collapsed in Genoa.
57% of the bridges in Switzerland’s national road network are more than 35 years old.
A chart in a 2016 report by the Federal Roads Office (OFROU), which presents the state of bridges, retaining walls and structures covering roads, classifies 14% as being in a less than satisfactory state – 12% defective and 2% bad. Fortunately, none are classified as alarming.
Swiss rules require every viaduct to be inspected every 5 years, and in 2016 CHF 718 million was spent maintaining Swiss national road infrastructure.
The last time a viaduct fell in Switzerland was in 1973 when a structure under construction in the canton of Neuchâtel tumbled down. Some construction workers were injured but no one died. An old RTS video shows the wreckage.
Maintaining road infrastructure is challenging and costly. Costs rise in line with the age of infrastructure. By 2030, annual maintenance costs in Switzerland are expected to reach CHF 1.16 billion, 62% more than in 2016.
Is there a risk the viaduct over Montreux near the Chateau de Chillon could fall? Civil engineer Jacques Perret told Tribune de Genève that even though there can never be zero risk, the maintenance has been done. Switzerland has the means he said. Eugen Brühwiler, one of the engineers involved in the maintenance of the viaduct in 2014 and 2015, told the newspaper that what happened in Genoa shouldn’t happen in Montreux.
In addition, the Montreux-Chillon viaduct is constantly monitored, according to the engineers.