A new school of traffic design says we should get rid of stop signs and red lights and let cars, bikes and people mingle together. It sounds insane, but it works.

Reversing decades of conventional wisdom on traffic engineering, Hamilton-Baillie argues that the key to improving both safety and vehicular capacity is to remove traffic lights and other controls, such as stop signs and the white and yellow lines dividing streets into lanes. Without any clear right-of-way, he says, motorists are forced to slow down to safer speeds, make eye contact with pedestrians, cyclists and other drivers, and decide among themselves when it is safe to proceed.

"The more you post the evidence of legislative control, such as traffic signs, the less the driver is trying to use his or her own senses," says Hamilton-Baillie. "So the less you can advertise the presence of the state in terms of authority, the more effective this approach can be." This, of course, is the exact opposite of the "engineering, enforcement and education" traffic-calming approach, which seeks to control the driver through the use of speed bumps, photo radar, crosswalks and other engineering and enforcement mechanisms

When it comes to reconfiguring streets as community spaces, ground zero is once again Holland and Denmark, where planners are removing traffic lights in some towns and cities, as well as white divider lines, sidewalks and speed limits. Research has shown that fatality rates at busy intersections, where two or three people were being killed every year, dropped to zero when controls and boundaries were taken away.

The ramifications go beyond safety, says Hamilton-Baillie, to bear directly on the interplay between speed, traffic controls and vehicle capacity. Evidence from countries and cities that have introduced a design speed of 30 kilometers per hour (about 18.5 mph) -- as many of the European Union nations are doing -- shows that slower speeds improve traffic flow and reduce congestion.

"This surprises many people, although mathematically it's not surprising," Hamilton-Baillie says. "The reason for this is that your speed of journey, the ability of traffic to move smoothly through the built environment, depends on performance of your intersections, not on your speed of flow between intersections." And intersections, he says, work much more efficiently at lower speeds. "At 30 miles per hour, you frequently need control systems like traffic signals, which themselves mean that the intersection is not in use for significant periods of time. Whereas at slower speeds vehicles can move much more closely together and drivers can use eye contact to engage and make decisions. So you get much higher capacity."

Combining slower speeds with a reduction in traffic controls, in other words, may have more than public safety and shared-space benefits. It also appears to profit the driver.

full artikel at Salon