An important feature of da Vinci’s town plans for ideal cities was the separation of pedestrian and vehicular traffic as illustrated in this design for a double-deck trussed bridge.
The first major two level bridge was the High Level Bridge across the River Tyne, England, completed to the design of railway engineer Robert Stephenson in 1849. It still carries rail traffic on the upper deck with pedestrians and one-way vehicular traffic on the lower.
The city of Chicago, USA has multi-level streets built in the 1920s that separate traffic, commercial and leisure activities much as da Vinci predicted.
The double-deck road and railway Minato cantilever truss bridge in Osaka, Japan (1974) and multi-lane double deck Tsing Ma suspension bridge over the Ma Wan Channel in Hong Kong completed in 1997 demonstrate how da Vinci’s ideas remain valid today.
Minato bridge, Osaka Japan
Photo: cowardlion / Shutterstock.com
The Tsing Ma Bridge