The first roundabouts in Europe were put in place by a French architect to alleviate growing traffic congestion in Paris, most of it caused by horse drawn carriages rather than motorised vehicles.
Eugène Hénard (1849-1923) was a French architect and a highly influential urban planner who devoted much of his life to finding solutions to growing traffic problem in his capital city.
By 1906 there were an estimated 65,543 vehicles in Paris. One of the most congested, and most dangerous places to circulate, even then, was the Place de l’Etoile, with the Arc de Triomphe in its centre and its 12 roads converging onto it, as there were no rules for moving round, entering or exiting the circuit.
In 1897, a British man, Holroyd Smith came up with the idea that there should only be movement in one direction in a circle. The concept was applied in New York in 1905 and then in 1907 by Eugène Hénard at both the Place de l’Etoile and the Place de la Nation in Paris.
Mr Hénard called them carrefours à girations. He also proposed subways for pedestrians from each street on the outer edge of the circuit, which would lead to a place in the centre, from where the person on foot could continue his journey in the direction of his choice without fear of being run over.
Eugène Hénard was also responsible for introducing the priority to the right system. Experiments with this method were begun in 1905 and the rule was included in the first official traffic regulations published in 1912. This rule of the road, often confusing to visitors from the UK, still stands in France today.
Hénard had many other ideas. He was in favour of ring roads around city centres and thought that traffic congestion problems were worse in Paris than other European cities because they had radial arteries connected to ring roads, which Paris lacked. He was a pioneer in traffic studies and broke down vehicles by type into domestic, professional and commercial to build up a detailed picture.
There is a legend that France has the most roundabouts in the world. This cannot be backed up as there are no official figures, but an article in Le Monde estimates there are around 30,000, with 500 new ones springing up every year, and one every 25km.
The article suggests their proliferation is down to former Prime Minister Jean-Marc Ayrault who was mayor of Saint-Herblain, Loire-Atlantique in the 1970s.
He solved the problem of a particularly dangerous junction with a roundabout after taking advice from a road traffic expert who had worked in the UK and seen how well they functioned there.
They first experimented with straw bales to avoid unnecessary expense, but were convinced and from then on the idea spread and from 1990 to 2000 there was an explosion of roundabouts across the country.