From tracks to motorways

We take our roads so much for granted that we no longer give them a second thought. The road construction industry meanwhile has had to adjust to people’s increasing mobility and the developments in vehicle technology. Here’s a brief look back over the history of road surfaces.

Dirt track

Erdweg

Dirt tracks do not have a solid bed and whether or not you can use them on foot or with transport very much depends on the weather. The damp subsoil is stabilised by the logs which are laid across it. Right up until the 18th century, most paths were simple dirt tracks. Where the ground was damp and low-lying, you managed with a layer of logs or laid cobblestones in towns and particularly exposed areas.

Rural road or paved road

Chaussee oder Kunststrasse

The rural roads that were built in the middle of the 18th century were the first transport routes since antiquity to be built with a solid bed from end to end. The rural roads consisted of a stone bed laid on natural ground, with raised stones wedged together, topped with a layer of broken rock and a final finer layer of crushed stone.

Macadamised road

Schotterstrasse

Scotsman, John Loudon McAdam (1756–1835), developed a simplified and therefore cheaper process for building solid road structures. McAdam based his principle on regular courses of crushed stone applied in layers which when compacted formed a single, consolidated layer.

Small sett paving

Kleinsteinpflästerung

Paving with small setts developed from a centuries-old tradition of cobbled streets. Originating in the 1880s, it was used particularly in towns and cities and on busy streets. This methodology for surfacing roads became widespread mostly in the 1930s and 40s. Small sett paving - as well as concrete roads - was regarded as the longest lasting and most skid-resistant surface - albeit the most expensive - until after the Second World War.

Asphalt road

Asphaltstrassen

Surface tarring involved spraying the dry macadamised surface with tar and gritting it with crushed sand. Tarring began to be used in Switzerland in around 1915 primarily to pick up dust in the streets, a problem caused by the advent of motorised traffic.

Synthetic bitumen

Bitumenbelag

Asphalt roads are the most common today. In cross-section, they consist of a solid, compacted macadamised layer as a foundation, a base course and a surface course. In the interwar period, there was only very limited use of various solid surface finishes locally, such as compressed asphalt and mastic asphalt. Instead, they were still using natural asphalt until the 1920s, which was mostly extracted in the Val de Travers region. Only when synthetic bitumen was produced as a by-product in the distillation of crude oil was the foundation laid for a more widespread application of the process.

Concrete road

Betonstrasse

The first attempts to construct concrete roads were made around 1910-20. At the end of the 1920s and in the 1930s, they were the first dust-free surfaces at all to provide a surface for heavy goods traffic with sufficient load-bearing capacity. Concrete road-building also introduced mechanisation to road-laying for the first time ever in the 1930s.

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