Along the state’s fastest-growing byways, road designers are trading their linear thinking for circular logic.
A new $6.7 million, dual-lane roundabout opens Friday in Marysville where Highway 9 meets 84th Street Northeast, a four-way crossing controlled, until now, by a traffic light.
Throughout the corridor, sprawl is changing Snohomish County’s landscape and adding congestion. To the east lies a woodsy oasis where people keep fruit trees and horse pastures; to the west are two-story homes, the Marysville Getchell high-school campus and a Wal-Mart a short drive south.
State data show 125 crashes there since 2001, and officials are predicting an increase of 22,000 daily car trips by 2035.
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Safety is the main goal in installing roundabouts, says Brian Walsh, traffic-design and operations engineer for the Washington State Department of Transportation (WSDOT). All drivers go through a roundabout at 15-20 mph, instead of cars abruptly stopping and accelerating between 0 and 50 mph.
There are roughly 290 roundabouts in the state, 110 of those on highways, Walsh said. Data on their effectiveness is limited, because while they have been around for decades in Europe, they are just gaining a foothold here.
Early findings in Washington state show that serious-injury crashes plummet, even as noninjury fender benders nearly double.
“Overall, it’s a safety plus,” said Russ Rader, of the Insurance Institute for Highway Safety. “The key thing is, you’ve eliminated the worst kind of crashes, the high-speed crashes.”
The institute says roundabouts reduce crashes by half. But its national numbers skew toward single-lane layouts, not the multiple-lane kind where drivers are exposed to sideswipes.
These are very distant cousins of the more than 1,300 tiny traffic-calming circles on Seattle’s residential streets.
There are no roundabouts on Seattle arterials, which are generally too narrow and hectic. “While they are an efficient way to manage motor vehicles, they are not so friendly for pedestrians,” said Dongho Chang, Seattle traffic engineer.
The change on Highway 9 makes some people uneasy.
George Schlosser owns the K9 Korral, a converted small farm two miles northeast. It houses as many as 110 dogs, brought from Arlington, Lake Stevens, Marysville and beyond, for day care or boarding. He doesn’t expect to lose loyal customers, but they’ve been complaining about the roundabout — which makes him think newcomers might not bother visiting K9 Korral in the first place.
The crossing’s record of one serious injury in the past six years is hardly enough to justify the cost to rebuild the intersection, he argues. The area’s worst crash, , happened in 2009 a mile north of the crossing, and was caused by a drunken driver.
Two weeks of roundabout construction caused its own havoc, by blocking east-west access. Diverted motorists have been making U-turns on Highway 9 just north of the circle, and there have been at least four crashes in the past two weeks, north of the circle. State troopers verified at least two occurred during a U-turn.
The project follows a two-lane roundabout in 2012 at Highway 9 near Arlington, and a pair of earlier roundabouts outside Bellingham on Guide Meridian Road. The insurance institute analyzed the Bellingham project and found fewer crashes, and calculated less carbon emissions. However, 40 percent of drivers said they sometimes use a nearby straight road to avoid the roundabouts.
State officials justify spending millions in Marysville based on counts that showed the 125 crashes since 2001 caused 5 serious injuries, 25 other injuries and 62 possible injuries. The crash types include 69 rear-enders, 33 involving left turns, and 16 side-impacts — and the leading causes were speeding, tailgating and inattention.
“Roundabouts force drivers to pay attention to what’s going on,” Rader said.
Drivers face a long learning curve.
At the 2-year-old Arlington roundabout, driver antics provide comic relief, said Jennifer Bjornson, manager of Coffee Cabana along Highway 9 there.
“It’s fun, because you’ve got everybody playing chicken,” she said. “If you’re not here doing it every day, you’re lost, and you almost end up crashing.” Occasionally someone goes the wrong way, and a few fast drivers “drift” the circle by spinning the rear tires, she said.
Dump trucks and boat trailers straddle two lanes. That’s unavoidable, said Rader, because a design big enough for trucks would enable too-fast car speeds.
Frances Hale, a longtime Marysville teacher, said the Getchell students will do fine in the new roundabout there. All traffic moves counterclockwise, “so you only have to look in one direction,” when entering the circle, she said.
Meanwhile, WSDOT says demands will grow, from 45,500 daily trips to 67,600 trips in 20 years. The state has a track record of guessing high, but Marysville in particular has grown sixfold to 62,600 people since 1990, and there’s still plenty of buildable greenfield space near the highway.
“We are building for the future and to keep traffic moving,” said project spokeswoman Kris Olsen. The roundabout is part of long-term plans to widen Highway 9 to four lanes, she said.
He said it used to take 20 to 40 minutes for drivers to leave the parking lot after school, but now it takes 2½ to 3½ minutes. However, noninjury collisions increased eightfold, to one a month.
Federal Way is even considering a three-lane, five-legged roundabout, near Todd Beamer High School, to include Enchanted Parkway South and a proposed Interstate 5 offramp. The entire $110 million makeover requires state money.
“A lot of people are nervous,” admits Rick Perez, Federal Way city traffic engineer. But to build a five-way intersection filled with traffic signals, left-turn lanes, stopped cars and wide pedestrian crossings would create what Perez calls “just an ugly beast.”