For decades, Seattleites have expressed frustration over motorists disobeying yielding rules and zipping through neighborhood intersections without signs.

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Driving too fast and oblivious of traffic yielding rules — it’s a menace at neighborhood intersections that drivers, bicyclists and pedestrians know all too well.

In his hilly Seattle neighborhood, Marvin Willis of Magnolia said he’s seen far too many close calls at intersections without stop or yield signs due to “drivers who don’t understand that you should slow down.”

Traffic Lab is a Seattle Times project that digs into the region’s thorny transportation issues, spotlights promising approaches to easing gridlock, and helps readers find the best ways to get around. It is funded with the help of community sponsors Alaska Airlines, CenturyLink, Kemper Development Co., NHL Seattle, PEMCO Mutual Insurance Company and Seattle Children’s hospital. Seattle Times editors and reporters operate independently of our funders and maintain editorial control over Traffic Lab content.

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For this week’s column, we took a dive into The Seattle Times archives to research neighborhood intersections, after Willis asked Traffic Lab about the number of unmarked residential intersections in Seattle and whether they are more prone to accidents than marked ones.

In our research, we found stories and columns over the years about neighborhood residents and city leaders mulling solutions to stop cars from unsafely zipping through narrow and steep residential streets.

A reader in 1965 wrote to The Times asking for stop signs at intersections near Seattle’s Delridge neighborhood based on the number of crashes there.

The push to curb unsafe driving on residential streets gained momentum in the late ’70s, as the city faced rapid change after the “Boeing Bust” era and later with Microsoft’s tech boom.

The popular solution at the time? Traffic diverters — concrete islands that can take a variety shapes, such as diagonals jutting into the street that aim to limit traffic to just drivers going to and from their homes, and in turn improve roadway safety.

“The devices have become part of the movement to make the city more livable,” a 1977 story said.

By the early ’80s, traffic circles became the hot trend.

Residents rallied support among their neighbors with petitions for the street additions to slow traffic. City officials decided whether to install a traffic circle based, in part, on an intersection’s history of collisions.

Seattle now has about 1,500 traffic circles, according to the city’s Department of Transportation (SDOT).

Traffic circles are included in what SDOT categorizes as “uncontrolled” intersections, crossroads without signs or lights to tell drivers who has the right of way. Roughly 60 percent of all Seattle intersections are uncontrolled, according to data provided by SDOT.

Like agencies across the country, SDOT says officials follow guidelines by the Federal Highway Administration while determining if an intersection should get stop or yield signs. The process includes researching the location’s crash history and traffic volume, as well as determining any visibility issues.

If three or more crashes occurred at a particular intersection over a year, or at least five within a two-year period, the intersection may qualify for a stop sign, SDOT says. Another condition is if more than 6,000 vehicles travel through the area each day.

The agency, however, does not install stop signs to slow traffic.

“When stop signs are installed as ‘speed breakers,’ accidents don’t decrease, and sometimes increase,” the department’s website says.

SDOT pointed to research that says because not all motorists safely stop at the signs, the signs can give pedestrians a false sense of safety. Also, vehicle speeds in an area may actually increase with stop signs since motorists tend to drive faster after stopping to regain time, the research says.

Whether unmarked intersections are more dangerous than marked ones is difficult to determine. That’s because all of Seattle’s central-city arterials are marked and usually have much more traffic.

In an attempt to reduce traffic-related injuries and fatalities, city officials recently lowered the speed limit for arterials from 30 mph to 25 mph, and for residential streets from 25 mph to 20 mph.

But beyond roadway changes, simply following driving rules would improve safety at intersections.

State law requires drivers to stop for people on foot or bikes waiting to cross at marked or unmarked intersections. And when multiple cars approach an intersection without signs or lights at the same time, drivers on the left must yield to those on the right.

At traffic circles, drivers turning left must proceed counterclockwise around the circle, although under certain cases, such as when parked cars are in the way, motorists can make left turns with caution, SDOT says.

Got a question?

Last week, we tackled a North Seattle reader’s question over the connection between public transit ridership and park-and-ride room.

If you have a question or idea for Traffic Lab, send it to We may feature it in an upcoming column.