9 million bicycles, but what about the cars in Beijing?

March 27, 2012

Forget the fact of there being "9 million bicycles in Beijing, that's not a fact. Indeed, motor vehicle traffic is fast becoming a big problem that has led to unsustainable pollution and draconian rules in some parts of the city. Now, Nan Ji of the Hebei United University in China and colleagues have developed an algorithm to help traffic planners optimize the flow of traffic across roundabouts.

Writing in the International Journal of Innovative Computing and Applications, Ji and colleagues at the Tangshan Tanggang Expressway Management Office and Tian Jin Polytechnic University explain how their models flow and figures out the largest traffic capacity through. The approach can compare the effects of using traffic signals in different modes or having such traffic controls disabled altogether. The system can also apply diversionary tactics to allow traffic to be channeled away from a particular roundabout at heavily congested times if possible.

In most cities, chronic and gridlock impede the flow of vehicles, wasting drivers' times and costing billions of dollars directly and indirectly as well as generating a sooty and smoggy carbon tracks across many. The roundabout was first posited as a way to smooth at the beginning of the twentieth century when there were many orders of magnitude fewer vehicles on the roads. Nevertheless, roundabouts with traffic signals to further control and prioritize traffic are being seen as the better option to conventional "crossroads" type intersections between stretches of road.

The team has considered three critical points in order to find a way to optimize roundabout implementation. They have looked at how to judge what controls might be needed with respect to traffic volume. They have looked at how delays at each entry and exit point on a roundabout might be balanced for the smoothest flow. They have also looked at how controlled flow compares with roundabouts with no traffic signals.

In testing the algorithm on a simulated roundabout in Beijing, and ignoring any number of bicycles, the team has found that they can reduce delays to just 11 seconds at the roundabouts' entry point with judicious timing of traffic signals.

Explore further: Roundabouts emerging as the ideal intersection between driver safety and efficiency

More information: "Mathematical model for designing the traffic circle control" in Int. J. Innovative Computing and Applications, 2012, 4, 58-66.

Related Stories

Organic traffic lights

June 30, 2009

Controlling road traffic in congested areas is difficult to say the least, a point to which any drive-time urban commuter might testify. An organic approach to traffic lights, might help solve the problem and avoid traffic ...

Dynamic toll for smooth-flowing traffic

August 12, 2011

Highway traffic can flow more freely thanks to a dynamic toll. Siemens has developed a special algorithm for traffic control systems that adjusts the toll charge to the current traffic situation. In return, the system lets ...

Smart traffic lights reduce fuel usage and lower emissions

October 27, 2010

(PhysOrg.com) -- Denso Corp. has designed the next version of 'the smart traffic light system'. By using messaging between vehicles and the traffic-light controller, better decisions about when to change signaling will help ...

Recommended for you

'Droneboarding' takes off in Latvia

January 22, 2017

Skirted on all sides by snow-clad pine forests, Latvia's remote Lake Ninieris would be the perfect picture of winter tranquility—were it not for the huge drone buzzing like a swarm of angry bees as it zooms above the solid ...

Singapore 2G switchoff highlights digital divide

January 22, 2017

When Singapore pulls the plug on its 2G mobile phone network this year, thousands of people could be stuck without a signal—digital have-nots left behind by the relentless march of technology.

Making AI systems that see the world as humans do

January 19, 2017

A Northwestern University team developed a new computational model that performs at human levels on a standard intelligence test. This work is an important step toward making artificial intelligence systems that see and understand ...

Firms push hydrogen as top green energy source

January 18, 2017

Over a dozen leading European and Asian firms have teamed up to promote the use of hydrogen as a clean fuel and cut the production of harmful gasses that lead to global warming.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.