Roundabouts, Circles, Carrefour Giratoire, call them what you will, the humble round road junction has helped the motorist get from A to B for over 110 years now.
I read a great article about them recently which talked about how towns try and make them pretty with sculptures and other artworks, however I thought it is worth delving into their history a little. Eugene Henard, a French town planner and architect designed the first however it was New York that can claim to be the first to install one. This is odd as the roundabout never really took off in the US – it was Europe and their old protectorates that really built them in vast numbers.
The idea is simple, keep the traffic flowing when the driver reaches a junction. Rather than waiting for a light to change or a policeman to allow progress, the roundabout simply allows traffic to merge and continue onwards. For low flows of traffic, everything works smoothly however when volumes increase, it can cause the same problem that it was designed to prevent – a backup of traffic entering the junction.
In most countries, drivers have to give way to vehicles already using the junction, however in some, it is the opposite – drivers already using the junction have to let others in which increases the traffic in the junction and defeats the purpose of the design! It is also common to see a lack of planning on or near a roundabout:
– I have seen every incoming road to a roundabout have a traffic light installed thus causing the problem that a roundabout is trying to fix – increasing rather than reducing congestion. In most cases the only roads that need lights on are the larger arterial roads leaving the smaller roads free to use the junction. The opposite way round would mean that the smaller road users would never enter the junction!
– Often you will see a secondary traffic management system too close to the exit of a roundabout causing a blockage of the junction. This could be a pedestrian crossing or other device that interferes with the smooth running of the main junction.
Britain which pioneered the “modern” roundabout – have they really changed in the past 100 years? – is also the home to the Magic Roundabout, named after a cult children’s stop-motion animation television show. The real name for the roundabout is actually a “ring junction”. There are now several of them in the towns near or to the west of London.
Some are a mix of 5 smaller roundabouts surrounding a larger inner counter-clockwise roundabout. One of the first to be constructed was based on a design by the British Transport and Road Research Laboratory – and is still considered a difficult junction to navigate!
Believe it or not – and this probably would only happen in the UK, there is a Roundabout Appreciation Society (UKRAS) who discuss the architecture and design of the road junction!
Meanwhile back in France, they are still trying to decorate theirs with art installations that showcase the towns that they serve.