How do you expand a tunnel when it has reached its traffic limit? Build another tunnel in parallel to it. That, at least, is what Lyon did and opened the 1.7km Croix-Rousse dual-tunnel system in 2013. The smaller, new €283 million tunnel has become a symbol of Lyon’s intention to reinvent itself as one of France’s most innovative mobility centres, said Mathieu Hermen, head of operations at La Metropole de Lyon.
Construction of the original two-lane tunnel under one of the city’s most densely populated arro