Traffic Roundabouts : Caltrans Plans to Go in Circles

In a scene from the movie “National Lampoon’s European Vacation,” Chevy Chase gets a laugh when he finds himself trapped in a British traffic circle, whirling frantically, unable to exit, for hours.

But here in California, the state Department of Transportation is not amused.

The agency hopes the state’s roads will someday be dotted with the doughnut-shaped intersections, called roundabouts, which, by eliminating stoplights and head-on traffic, have been credited with saving lives and easing gridlock throughout the United Kingdom.

Minimizing the possibility of head-on and broadside collisions, roundabouts have been credited with reducing accidents by 40% to 60%, and fatal accidents by as much as 85%, according to several studies in Britain and Australia.

Search Launched

Convinced that the roundabout can do the same for California’s congested streets, Caltrans has launched a search in Los Angeles and Ventura counties for an intersection of two state highways to serve as a test site.

If constructed, the British-style circle--which differs from most existing American rotary intersections by assigning right-of-way to cars already traveling around the center island--would be the first of its kind in California.

“This is a great chance to do a service for humanity,” said Al Maas, a senior Caltrans engineer who retired in July from the agency. “We have an obligation to try this thing out.”

So far, that has not been an easy task. Caltrans spent the last two years trying to convince Ojai residents that the two state roads intersecting in the small Ventura County community would be an ideal spot to showcase the device.

Many of the town’s 7,850 residents, however, balked, fearing that they would be guinea pigs in an experiment doomed to end in confusion, if not tragedy.

Shunned by Professionals

Skepticism is also shared by many of the nation’s traffic professionals, who long ago shunned rotaries, such as those found in Long Beach, Bakersfield and spots throughout the East, for their tendency to bog down during peak hours.

Some worry, too, that timid drivers may panic, a la Chevy Chase, and get trapped by more aggressive motorists whizzing around the circle.

“To many people, it’s a very uncomfortable experience,” said Ernie Flores, senior traffic engineer for Long Beach, where a rotary marks the intersection of California 1 and California 19. “Although traffic circles may look pretty, they’re really not that functional.”

Caltrans hopes to prove them all wrong. While the British roundabout doesn’t look much different from America’s older, chaotic rotaries, which flourished in the 1920s and ‘30s, advocates say it keeps traffic flowing far more smoothly.

“The thing is to get the first one built,” said Leif Ourston, a Santa Barbara engineer who was Caltrans’ consultant on the Ojai proposal. “Once they catch on, you’ll see people demanding them and cities requiring them.”

Those benefits stem primarily from the British right-of-way rule, which calls for approaching motorists to yield until there is a gap in the circulating traffic, Ourston says. In most U.S. rotaries, entering motorists do not have to yield and often bring traffic screeching to a halt when they merge into the circle.

In addition, the roads feeding a roundabout intersect the circle at a nearly perpendicular angle, forcing motorists to slow down and yield to circulating traffic. By contrast, most American rotaries are designed so that motorists hit the circle at a less steep angle, allowing them to maintain their speed and cut off cars traveling around the island.

Finally, the feeder roads to a roundabout flare out to three or four lanes just before they meet the circle, permitting several cars to enter simultaneously at peak traffic hours.

Battling Inertia

“Those improvements mean the difference between a smooth-running pleasant situation and a white-knuckle situation,” Ourston said. “The subtleties really matter.”

While some U.S. traffic circles employ some of the same design features as roundabouts, none are exact copies of the British model and do not perform as well, Ourston said.

Some, for example, have no yield stripes on the highway, he said. Other minor deviations, such as pedestrian crossing islands and parking along the perimeter of the circle, add to confusion and hinder the smooth flow of traffic.

“What Caltrans is doing is absolutely unique,” Ourston said. “We’re trying to bring the state of the art and demonstrate it here in America.”

But many traffic engineers, even if they accept the merits of the improved British version, say they are reluctant to experiment with such unfamiliar concepts, especially in today’s litigious society.

Others point out that American drivers have grown accustomed to traffic signals and stop signs, tools that regiment the flow of cars and reduce the need for individual judgments on the roadways.

“The English are very civilized. With our drivers, it’s every man for himself,” said John Cavallero Jr., traffic engineer for New Haven, Conn., where officials have removed all the city’s rotary intersections. “With a roundabout circle, it’s left up to the driver how to behave.”

Roundabout advocates, however, say the circles are not so difficult to negotiate and have met with success in such diverse driving environments as France, Iraq, Thailand and Australia.

“American drivers are pretty sophisticated,” said Bernie Dennis, traffic engineer for Orange, where a large rotary, close in design to British versions, has bounded the city’s central plaza since the turn of the century. “Compared to some of the complex freeway interchanges we have here in California, a rotary is like a slam-dunk.”

Watching Cars, Not Lights

Additionally, they say, the roundabout’s lack of regimentation actually creates a safer environment because it forces drivers to keep their eyes on other cars rather than a mechanized signal.

“The driver should be getting his cue from something directly related to the object that could cause him danger,” said Frank Blackmore, a traffic engineer in Wokingham, England, who served as Ourston’s adviser on the Ojai project. “That’s much clearer and more natural than looking at a dumb light up there that just turns red or green.”

Blackmore, widely regarded as the father of the modern roundabout, began fine-tuning the intersections in the early 1960s while at the British Transport and Road Research Laboratory, where his work later earned him England’s prestigious Wolfe Award for engineering achievement.

Ourston, who met Blackmore in 1979 while doing research at the laboratory, returned from England impressed by the ability to drive for hours across the countryside and never stop for a traffic light.

It was not until 1985, however, that Ourston, a former city transportation engineer in Santa Barbara, was able to spark interest at Caltrans, which already had plans to renovate the signals at the Y-intersection of California 150 and California 33 in Ojai.

23 Accidents at Site

The intersection, while not considered a major hazard, had been the site of 23 accidents over the previous three years. Ourston predicted that the number could be cut in half.

“Gosh, as professionals, we couldn’t overlook that,” said Caltrans engineer Maas, who in the fall of 1986 first broached the idea with the Ojai City Council.

Although Caltrans, which budgeted $250,000 for the project, was not required to obtain permission from Ojai officials, the agency had said it would not proceed without local support.

In a letter to Caltrans in October, 1987, then-Mayor Frank McDevitt expressed “cautious support” for the plan but conceded that “something as new and different as a roundabout naturally, and justifiably, creates some apprehension.”

Those mixed feelings also pervaded the town, known for New Age meditation centers and fervent environmentalism. The merits of the roundabout were debated in the banquet rooms of half a dozen service clubs, in the chambers of City Hall and in the pages of the Ojai Valley News, circulation 6,500, which even sent a reporter to England for four days to circumnavigate one herself.

Critics, calling themselves Citizens for Safe Driving in Ojai, drafted a scathing report on the “roundabout fantasy” that claimed the project “will not only cost money and result in confusion, but may also cost lives.”

Concern for Pedestrians

Led by Craig Walker, a computer and psychology teacher at the town’s only public high school, the group voiced particular concern about the ability of bicyclists, equestrians and pedestrians to negotiate the circular intersection. Their anti-roundabout petition was signed by 2,500 residents.

“People just didn’t feel we should be guinea pigs for this,” Walker said.

A few rallied to the roundabout’s cause, such as William Noack, who served English ale among the antiquarian texts at his Time Portal bookstore and hung a giant banner that urged passers-by to heed “Facts not Fear.”

But Caltrans officials said they could see the writing on the wall and, discouraged by the prospect of a November vote on the issue, announced on June 17 that they would seek another site.

To avoid some of the dissent encountered in Ojai, the agency will not propose a roundabout for an intersection that already has traffic lights, said Gary Bork, chief of traffic operations for District 7, which spans Los Angeles and Ventura counties.

Instead, Caltrans will be looking either to construct a roundabout at a new intersection or to convert an existing intersection that has only stop signs.

“I think it’s just a matter of weeks before we find another location,” Bork said. “The time has come for it.”

IS THE ROUNDABOUT IN CALIFORNIA’S FUTURE? Caltrans is considering experimenting with the British-style traffic roundabout in California. The British drive on the left. Roundabout shown is adapted for U.S. drivers. British-Style Roundabout

Entering cars yield

Cars’ path is deflected by center island

Entering lanes flare out from one to several American Traffic Circle

Entering cars don’t yield

Cars hit tangent of circle and flow right into traffic

Cars enter single file