It was bound to happen. The neo-traditionalist planning movement is making inroads into the most doctrinaire of planning dynasties – Caltrans. Late last year, in a little-noticed but potentially monumental policy shift, the state road bureaucracy issued Design Information Bulletin Number 80, thereby granting guarded approval of modern roundabouts as part of California's highway design toolbox. Now it's up to local governments to press ahead with a back-to-the-future concept: intersections where signalized or controlled stopping and multiple turning movement lanes are replaced with slowed, continuous, circular movement patterns around landscaped or art-bedecked center plazas. The concept of one-way circular intersections was probably invented by French architect Eugene Henard during the 19th century. His American counterpart William Eno was simultaneously proposing small circles to alleviate traffic congestion in New York City. But the idea never flourished, and implementation remained limited to grand urban design locations like Du Pont Circle in Washington DC. The notion that the roundabout could actually enhance intersection operation and safety really took root in England during the mid-1960s with the innovation of the "yield-at-entry" rule and the "angle-of-deflection" design. These features combine to slow entering cars, allow only one point of conflict, and keep traffic moving in accordance with its load characteristics. These minor but critical design improvements enabled the safe handling of much higher volumes of traffic. The roundabout concept has flourished in many countries since then – notably in France, the Netherlands, and Australia. But, interestingly, in North America the idea has been slow to take hold. One wonders if the simplicity of the concept offends our more techno-fix oriented engineers. But there is movement. Led by roundabout consulting crusaders like Florida-based Michael Wallwork and Santa Barbara-based Lief Ourston and Peter Doctors, the modern roundabout is an idea that is, well, coming around. And it's no wonder why. Not only do the roundabouts dovetail nicely with growing preferences for new urbanist design, but, importantly, they seem to really work. A growing body of empirical evidence suggests that roundabouts can handle more traffic, reduce injury collisions, and save capital and operational costs. Plus, they're fun to tool around in. In the mid 1990s, Vail, Colorado, took a groundbreaking risk in tackling the interchange design at Vail Road and Interstate 70, which is the freeway that funnels Denver's weekend skiers into the Rocky Mountain resorts. The solution was a double roundabout design that saved $3 million in capital costs by eliminating the need for a bridge widening and $85,000 per year in traffic police staffing. Interchange capacity grew by 56% while injury crashes have eased by 66%. California trails in the acceptance of roundabouts. Instead, Florida, Colorado, and Nevada are at the leading edge. With Bulletin 80, Caltrans has taken a baby step toward acceptance. But it will be the local jurisdictions that must take the lead. In California, Santa Barbara, Santa Maria, Carlsbad, and Arcata are at the forefront. In each case, local planners have served in advocacy and education-dispensing roles. In Santa Maria's case, the developer of an adjacent big-box center financed two roundabouts in 1998. Reluctant to be guinea pigs for an intersection experiment, the developer winded up benefiting from the cheaper cost and from the unique design features that serve as entry points. According to Jim Stern, city planner, the facilities are functioning well, but there were administrative bugs. "We had a bit of a problem with the signage component," Stern said. "Because there is no roundabout signage approved by Caltrans, we have not been able to install the internationally-accepted roundabout approach signage." Tiny Arcata in Humboldt County is the epicenter of California's roundabout trend. The city, which is proud of the fact that it has no traffic signals, has one circle on line, two beginning construction later this year, and three more scheduled for the summer of 2000. According to Dobie Class, assistant public works director, the city is retrofitting existing intersections to make them safer and to avoid the costs of signals and maintenance. Santa Barbara traffic consultant Scott Schell said the transportation community in the state is "cautiously optimistic" about the future of modern roundabouts. "We certainly look at them in specific instances where it appears to be a feasible alternative. The general feeling is ‘let's try them at smaller locations and see if they work,'" Schell said. He added that even though vehicle collisions have been reduced, engineers are insecure about data on the safety of pedestrians and bicyclists. But Ourston asserted that there have been no pedestrian collisions involving roundabouts in the U.S. As the new urbanist movement has demonstrated, sometimes what's old is what's new. And in matters of traffic, this may mean we will be going in circles.