You've heard of a roundabout, haven't you? It's an intersection without traffic signals, in which vehicles don't go straight through but veer slightly out of their way to circulate around an island in the middle.
A roundabout is safer because drivers arent tempted to risk head-on or T-bone collisions while racing to beat a red light. But it's also quicker and less polluting because drivers arent forced to stop and idle.
But a roundabout would not significantly help low-traffic streets that may not see 28 vehicles in ten minutes. Throughput is not the only measure of a good intersection. Another consideration is how much land is required. At Tech City in London, the buildings on opposite sides of this roundabout are more than 300 feet apart.
to home, heres a smaller pseudo-roundabout, only 100 feet from
curb to curb. The Ohio village of Mt. Gilead acquired it at the
end of World War I, when Senator Warren G. Harding dedicated a
Victory Shaft in the center of the town square. Cars on Main
Street or High Street have to wait for a green light and then swerve
around the obelisk in a counterclockwise fashion.
What fraction of intersections are roundabouts? Over two percent in more advanced nations like France, but less than one percent in the United States. Zachary Crockett observes, Circular traffic intersections in the U.S. are feared, avoided, and even loathed often without good reason. It seems that every time traffic engineers propose to build a new one, there is protest and uproar. Conservatives resist changing the good old ways. Why not drive straight across?
Nevertheless, the Pennsylvania Department of Transportation (PennDOT) is starting to replace some traffic lights and stop signs with better intersection designs, including roundabouts. One was installed in a Pennsylvania borough near me. That would be Rochester, the hometown of Christina Aguilera.
Most of Rochesters streets are laid out in a standard grid pattern, but Brighton Avenue slices diagonally through the center of town. That results in a cluster of odd angles. In 2005, a driver starting from the bottom edge of this view might have had to wait at a traffic light to cross Brighton, then wait again to turn left on Adams Street, then wait again to cross Brighton again.
Sometimes it took seven minutes to get through all the lights. Buses were trapped in the gridlock and riders missed their connections. Some 600 local drivers a day went out of their way to avoid this area.
Using a state grant, the Beaver County Transit Authority spent $1.8 million to replace the intersection. When the new roundabout opened in 2012, it reduced congestion by at least 80%. The Pittsburgh Post-Gazette reported, Cars, trucks and buses glided with almost no delays through a hub that once featured long waits for traffic signals, frayed nerves and crashes. BCTA general manager Mary Jo Morandini said, Its been a major success. The community really loves this project.
Hows it work?
Youll encounter four exits besides the street you came in on. When you reach the street you want, simply bear to the right again to exit. If you miss your turn, just continue for another lap and get off the next time around.
Exploring the layout from ground level, I was slightly uncomfortable at the crosswalks. There are no lights to halt vehicles and flash a walk signal to pedestrians.
I tried to wait until the oval was empty before walking across the outbound half of a street.
PennDOT statistics show that roundabouts generally carry about 30% more vehicles in peak traffic than signalized intersections and reduce fatal crashes by 90%. Zachary Crockett writes, Roundabouts are safer, more environmentally-friendly, and more efficient than signalized intersections. ...They allow the elimination of ever-wasteful left-turn lanes ... freeing up more space for bike lanes and landscaping. By negating the need for traffic lights, roundabouts also save an estimated $5,000 per year per intersection in electricity and maintenance.
Still, Crockett continues, America has its reservations. Why? According to British journalist Stephen Beard, The roundabout is said to have flourished in Britain because it requires the British virtues of compromise and cooperation, [in contrast to] the U.S.s more aggressive, confrontational culture.
Wes Siler notes, Americans don't just care about getting where they're going quickly; they care about getting there quicker than the next guy. They exercise their divine right to cut other people off. Installing a merge at every intersection in the country would result in either a nationwide traffic jam or a huge spike in the violent crime rate. Probably both. People have guns here.