By Dan Winn
Even a transportation novice observing the graceful traffic flow around Ellijay’s bustling town square in Northeast Georgia would come away mystified that there are so few circular intersections, or “roundabouts,” in the state and the nation.
Like Ellijay’s 2-year-old roundabout surrounding a memorial to slain warriors, these traffic devices have a whole lot more than grace going for them. As a more efficient method of moving traffic through most intersections, they have the potential to save this nation millions of gallons of gasoline and millions of hours in commute time, all while reducing traffic deaths and injuries.
A roundabout, in its simplest form, is a circle of road that surrounds a raised island in the middle of an intersection. Vehicles must move around the island to continue on their route, yielding to vehicles already in the circle. Vehicles can enter from each leg simultaneously.
Unfortunately, transportation engineers are locked into the mode of correcting every intersection by installing stop lights or, in the vast number of city outskirts, three- and four-way stop signs. These are almost universally an impediment to the smooth flow of traffic.
A survey by the Insurance Institute for Highway Safety cites the effectiveness of circular intersections. It found a 76 percent reduction in injury-producing crashes and 39 percent fewer crashes overall at modern traffic circles compared with intersections using signals or stop signs. In addition, the institute estimates, roundabouts reduce the number of fatal and incapacitating injury crashes by an astounding 90 percent!
Considering that some 800 traffic deaths take place at traffic-light intersections, along with about 200,000 injuries, a roundabout ought to be among the first options considered in planning. It has the effect of slowing traffic entering and exiting the intersection while maintaining a constant flow of traffic. That’s not small potatoes in Georgia’s gridlocked cities and suburbs; the average commuter in Atlanta wastes 53 hours and 84 gallons of fuel sitting in traffic every year.
In recent years, France has created roundabouts at the rate of about 1,000 a year – the leader, with more than 12,000 roundabouts; while hundreds exist in Britain, in Norway, in Sweden and in the Netherlands.
Two of the United States’ earliest, best and most prominent modern roundabouts were built in Vail, Colorado, in 1995. Commuters benefited when waiting time was nearly eliminated after Vail removed the stop sign-controlled ramp and frontage road intersections at its main entrance from I-70, replacing them with the pair of roundabouts. Thanks to the $2.2 million improvement, peak-hour traffic flow increased 10 percent.
The good news for taxpayers is that Vail’s roundabouts cost one-seventh the estimated cost of typical interchange capacity improvement projects, which involve widening the bridge and installing stop lights for about $15 million. More than $50,000 annually is saved by not needing two officers to direct traffic at the intersections. Roundabouts also offer far lower maintenance costs than traffic signals, which cost $3,000 per year in electricity, bulb replacement and other maintenance.
Even better news was that crashes declined from an average of seven per quarter over previous years, to an average of four per quarter, with no fatalities, after the roundabouts were constructed. Vail is no aberration, either. “Roundabouts, an Informational Guide,” published by the federal Department of Transportation in 2000, reported that, “Experiences in the United States show a reduction in crashes after building a roundabout of about 37 percent for all crashes and 51 percent for injury crashes.”
Because modern roundabouts require all drivers to slow, turn and yield before entering the intersection, crash rates are lower than at traffic signals. And because traffic moves at just 10-15 mph through the roundabout, crashes are much less likely to cause injury or death. When properly designed, injuries for bicyclists and pedestrians at roundabouts sharply decline, too.
After seeing the interchange easily handle heavy traffic during a terrible blizzard in the first week of 1996, both Vail newspapers printed apologies for their earlier opposition to the project.
Roundabouts are typically up to 30 percent more efficient than traffic signals, partly because there is no wasted red and yellow light time. That adds more capacity than at a signalized intersection. The reduced delay can also reduce air pollution from idling vehicles. Additionally, vehicles are quieter because of lower speeds and reduced braking and acceleration noise. By getting rid of the “expressway” look and feel of many arterials, they help reduce speeding nearby. And, as in Ellijay, the landscaped island in the center offers the chance to create more beauty and can be a focal point enhancing the town square.
It’s peculiar to nag citizens to turn off a few lights at home when so many useless traffic lights are burning energy 24 hours a day. The savings in gasoline, construction costs, lost time and electricity are really astronomical money bonuses over and above the lives and injuries saved by roundabouts. Legislation to raise the gasoline mileage of sport-utility vehicles by a few gallons over a six-year period is trivial compared to a solid program of roundabout construction.
Dan Winn, a retired Superior Court judge who lives in Cedartown, wants to see Georgia transportation planners come around to roundabouts. The Georgia Public Policy Foundation is an independent think tank that proposes practical, market-oriented approaches to public policy to improve the lives of Georgians. Nothing written here is to be construed as necessarily reflecting the views of the Georgia Public Policy Foundation or as an attempt to aid or hinder the passage of any bill before the U.S. Congress or the Georgia Legislature.
© Georgia Public Policy Foundation (September 26, 2003). Permission to reprint in whole or in part is hereby granted, provided the author and his affiliations are cited.