Advertisement

Street Smart

City Smart / How to thrive in the urban environment of Southern California : A Roundabout Route to Solving Traffic Problems

February 23, 1996|LUCILLE RENWICK | TIMES STAFF WRITER

On a recent trip to Ghana, as our tour bus cruised through the bustling capital of Accra, our tour guide announced that we were in the "city of rotaries."

Indeed, because of Accra's frequent power outages, the sprawling metropolis doesn't have a single traffic light. Instead the city is thick with traffic circles and cars whirling around the circular islands at speeds up to 40 mph. But somehow, despite the appearance of chaos, the traffic circles work with minimal problems.

Traffic circles--or rotaries if you hail from Boston, roundabouts in Great Britain and elsewhere--feed incoming traffic at intersections into a circle, from which drivers pick their desired exit and peel off. The advantage is that all vehicles are moving at slower speeds and in almost the same direction, not at right angles to one another as in the common cross-shaped American intersection.

But to many Americans, traffic circles have a nightmarish image. They are those confounding nuisances that kept Chevy Chase and his family reeling hopelessly for hours in the movie "National Lampoon's European Vacation."

But a host of American traffic and transportation engineers in Southern California and around the nation are trying to improve traffic circles' sullied image. And they say the circular roadways may just be the wave of the future, replacing the intersections and traffic lights to which we've grown so accustomed.

"I'm sure roundabouts will come into favor," said Leif Ourston, a traffic engineer and president of Ourston & Doctors, a Santa Barbara-based engineering consulting firm that specializes in roundabouts.

"Accident rates at roundabouts are lower than at cross-intersections" because the speed is lower, he said. "The biggest negative is that people don't like change."

Traffic circles have long been a fixture in most European and British cities and many parts of the northeastern United States, especially throughout Massachusetts. The concept originated in New York and Paris at the early stages of the automobile age, serving as community gathering places and when necessary, positions from which troops with artillery could command many roadways when battling rioters.

For several years, while horse-drawn buggies were common, cars were new and collisions were few, the rotaries were successful. But when the automobile revolution took off between 1900 and 1940, mayhem and congestion at rotaries became a problem. Eventually, New Jersey, New York and Maine began replacing them with intersections.

"They just don't seem to fit the decorum in certain areas, especially in Boston," said Howard Mansfield, a freelance writer who has written extensively about traffic circles. "You feel like you're in an uncontrolled situation when you're in the middle of a traffic circle."

However, in such European countries as Denmark, the Netherlands, Britain, Germany and Sweden, roundabouts are being built at the rate of 80 to 100 per year because of their high success rate, said Per Garder, a professor at the University of Maine who studies traffic circles.

Although the West Coast has fewer traffic circles than the east, the European influence made its way here. Wilshire Boulevard and Western Avenue were the site of a small, experimental traffic circle in 1922. And a flagpole is one of the last remnants of a traffic circle at Colorado and Orange Grove boulevards in Pasadena.

Several antiquated traffic circles are still in use in various parts of Southern California, including Venice, Santa Barbara and the city of Orange. But they are the old-fashioned type, in which drivers making the circle do not have right of way over new arrivals. That's the main problem, said Ourston, who has led the implementation of roundabouts throughout the western United States.

The modern designs, now referred to as roundabouts by traffic engineers, follow a right-of-way rule under which arriving motorists must yield to those inside the circle, he said. The roads feeding a roundabout intersect the circle at a nearly perpendicular angle, forcing motorists to slow down and yield to circulating traffic. At peak traffic times, modern roundabouts can handle as many as 5,000 cars per hour, Ourston said.

One such roundabout is in Long Beach, where an old-style traffic circle was converted in 1990 by installing yield signs at the incoming lanes and providing more feeder lanes. Another, smaller modern roundabout was built in Santa Barbara in 1992. And a roundabout is in the works in Calabasas.

But some Caltrans officials contend that roundabouts are too new and problematic to install at onramps or offramps.

"Caltrans isn't opposed to the concept, but they haven't been tested in the U.S. and until they're proven we don't want to go hog wild," said Alan Glen, chief of geometric design standards at Caltrans.

And it doesn't appear likely that the circular roadways will find their way to Los Angeles streets any time soon.

A proposal by a neighborhood coalition in 1994 to build a small roundabout at Mulholland Drive and Beverly Glen Boulevard was rejected by the city's transportation officials because "it wouldn't work worth a darn," according to senior transportation engineer Tom Jones.

But Ourston cites examples such as Vail, Colo., where a roundabout installed in October at a busy onramp to Interstate 70 has already reduced delays, congestion and accidents.

"People think traffic circles have failed because of our drivers," Ourston said. "But it was the engineers who got the designs wrong, not the drivers navigating through the circles. When we engineer them properly, like in Vail and Long Beach and Santa Barbara, they work as well as [in] any other country."

Comments on Street Smart can be sent to Lucille Renwick at: lucille.renwick@latimes.com

Advertisement
Los Angeles Times Articles
|
|
|