Featured Stories

Other Pamplin Media Group sites

Local Weather

Cloudy

55°F

Portland

Cloudy

Humidity: 86%

Wind: 0 mph

  • 24 Oct 2014

    Rain 58°F 50°F

  • 25 Oct 2014

    Rain 63°F 48°F


3, 2, 1 ... STOP WALKING

Countdown clocks changing way Portland walks, drives


by: TRIBUNE PHOTO: JONATHAN HOUSE - Peter Koonce is in charge of traffic signals for the city of Portland, where all pedestrian signals will have countdowns by the end of 2014.Amy, who lives in Sherwood but works in downtown Portland, has a rule. If she arrives at an intersection and the pedestrian timer has counted down to four or less, she stays put and waits for the next walking phase. Five or more, she crosses.

“I like it,” Amy says of the countdown signal at Southwest 10th Avenue and Burnside Street, right in front of Powell’s City of Books.

Randy Wagoner, a tourist from Cherryvale, Kan., favors countdown pedestrian signals as well, though for a different reason.

As he waits to cross Burnside on his way to Powell’s, Wagoner explains that the countdown tells him how fast he has to walk, or maybe even run.

“I always push it,” he says. “If there’s less time I hustle.”

Portland pedestrians used to see only Walk or Don’t Walk, or a walking or standing figure telling them what to do. But in 2002 Portlanders started getting what traffic professionals call countdown signal timers. About 870 of the city’s 1,080 traffic signals feature the countdown.

Sometime next year, the transition will be complete and all pedestrians will be confronting the countdown, except for jaywalkers. The countdowns are supposed to keep pedestrians safer. And they do, according to a slew of studies. Whether they keep drivers safer is a matter of which study you believe.

San Francisco engineers found the number of pedestrians still crossing when their traffic light turned red decreased to 9 percent from 14 percent once countdowns were installed. The San Francisco study found little change in when pedestrians started crossing. But the difference occurred in the intersection — pedestrians like Wagoner, caught still crossing with a countdown signal heading closer to zero knew to pick up their pace to make it across the street in time.

Walkers benefit; drivers don’t

A large-scale study by the Michigan Department of Transportation looked at intersection crash reports and found fewer pedestrians getting hit by cars where countdown signals were employed.

The Toronto Transportation Division in Canada looked at every accident at 1,794 Toronto intersections during the course of five years and found that while pedestrians were safer with countdown signals, car crashes at countdown intersections increased 5 percent — an extra 21 collisions citywide. More cars were hitting other cars at intersections with countdown signals.

According to the study, the crash increase is greatly due to an increase in tailgating among drivers who, because of the countdowns, know when their green is about to turn yellow and speed up to try to make the light. In fact, the authors of the Canadian study suggest that engineers consider a device that would hide the pedestrian countdown from oncoming drivers.

Ironically, countdown timers in the United States and Canada are only on the pedestrian signals, unlike in Europe, where the traffic signals for drivers also have countdowns. Which means those Toronto drivers and their Portland counterparts are looking at the pedestrian countdowns when they decide to speed up.

Mike, about to cross Burnside on his way to Powell’s on this Monday morning, admits that’s exactly what he does when he’s driving.

“It tells me whether I can gun it or not,” says Mike, visiting Portland from Roseville, Calif.

All signals aren’t same

by: TRIBUNE PHOTO: JONATHAN HOUSE - Pedestrians on West Burnside near Powells bookstore get 12 seconds on the pedestrian crosswalk timer, a standard one second for three and a half feet of roadway.Eric Bradley, on the other hand, finds the countdown timers confusing. The downtown Street Roots vendor finds crossing Burnside in front of Powell’s particularly difficult, with 10th Avenue drivers trying to make left turns around pedestrians.

“It’s too short right here,” Bradley says “Some lights are too long, and some lights are too short, and I find myself running across the street a lot.”

To make matters more confusing, some timers reach zero when the traffic light turns to yellow, but others hit zero when there are still a few seconds of green light for drivers.

That extra green happens on side streets, says Peter Koonce, who manages traffic signals for the Portland Bureau of Transportation. Cars are setting off sensors underneath the pavement, holding their green signal longer and allowing them to make right turns after pedestrians have cleared the crosswalk.

Incidentally, Koonce says that by law pedestrians here are required to be completely crossed by zero. In addition, Oregon pedestrians cannot enter an intersection if the pedestrian signal is flashing its Don’t Walk hand, regardless of the countdown number. Other states don’t care when pedestrians start across, only that they are fully across by zero.

Countdowns work because they give pedestrians more information, according to Koonce. “People never understand the flashing to walk,” he says. “The countdown gives them a sense of what it is they’re supposed to be doing.”

Koonce isn’t a fan of drivers peeking at the pedestrian countdown because that means they aren’t paying as much attention to oncoming traffic, which may or may not have a left-turn signal.

Site-specific signals

The countdowns, according to Koonce, give pedestrians three and a half feet per second. Wider crossings get longer countdowns. Downtown, some intersections have 6-second countdowns. The city’s longest is at Southwest Barbur Boulevard and Capitol High way, a 125-foot crossing with a 32-second countdown. But that Barbur crossing has been outfitted with a special push-button video camera to detect pedestrians who might not be making it across before zero. In those cases, the traffic signal is programmed to extend the red until the pedestrian is across.

Even fancier is the experimental thermal-imaging camera at Southeast 39th Avenue and Lincoln Street. Bike riders had requested a change there because small children on bikes heading east on Lincoln were having a hard time getting all the way across by zero. A regular video camera had difficulty detecting the tykes and their bikes, but the thermal imaging camera can differentiate between bikes and cars and hold the light when necessary.

However, there may be an advantage to drivers stopped at red lights peeking at pedestrian countdowns, says David Hurwitz, an engineering professor who studies traffic signals at Oregon State University. Hurwitz is studying efficiency rather than safety.

Specifically, he’s looked at left-turn signals, and the lost startup time that occurs when a red traffic light turns green. Ideally, all the cars are ready to hit the gas and move into the intersection. But people get distracted, or their reaction times are slow. So one or more of the first five cars in line often are late getting started, resulting in fewer cars moving through the intersection on the green. After 6,000 intersection observations, Hurwitz reports a 3 to 9 percent loss of efficiency at most intersections due to driver inattention.

Hurwitz has noted at which intersections those first five drivers efficiently get through the intersection without leaving large gaps.

“It’s only working that way here if drivers are peeking at the pedestrian timer,” he says.

Steph Routh, executive director of pedestrian advocacy organization Oregon Walks, likes countdown timers and especially likes the idea of site-specific signals. She says senior centers have approached the transportation bureau for longer countdowns at signals near their locations, and the bureau has complied.

But Routh doesn’t like that extra green that drivers sometimes get after the pedestrian timer has reached zero. “Now I can see the drivers get preferential treatment,” she says.


Traffic Trivia

The particular color for pedestrian “Don’t Walk” lights is known worldwide as “Portland Orange.” Portland traffic officials say they have no idea how the name became matched with the color.