The Seattle Department of Transportation says "skinnying" up a portion of a city street could reduce the risk of crashes and increase traffic flow, making it safer for both drivers and pedestrians.

The idea, called a "road diet," is one of two options the city is considering to improve pedestrian safety along city streets. Another option is to remove the uncontrolled marked crosswalks.

The proposed changes are based on a 2002 federal study on pedestrian safety, which found that marked crosswalks without lights can be more dangerous to pedestrians than no crosswalk at all.

Uncontrolled, "high risk" crosswalks a "multiple lane threat," said Peter Lagerwey, supervisor of the city's bike and pedestrian safety program.

For example, pedestrians have hard times finding a gap in which to cross the street on four-lane roadways and reducing the number of traffic lanes they must cross is one way to make it safer, he said.

On a four-lane street, drivers change lanes to pass slower vehicles, such as those waiting to make a left turn or stopped for a pedestrian. When there are two lanes of travel, the lead vehicle controls driver's speeds and actions, said Wayne Wentz, a traffic manager for the transportation department.

A center turn lane would also improve motor vehicle access, said Wentz. A similar configuration is already in place on California Avenue.

Road diets have been implemented in hundreds of cities across the country without significant setbacks to travel time, said Dan Burden, executive director of Walkable Communities, Inc., a non-profit aimed at helping neighborhoods become workable places for everyone, not just cars.

Generally, truck drivers prefer road diets because it makes lanes wider and provides a better turning radius when bike lanes are present, he said.

"They (industry leaders) may be expressing concern out of fear rather than knowledge," said Burden, a widely regarded expert on street corridor and intersection design and traffic management.

Burden co-authored an article with Lagerwey in 1999 entitled, "Road Diets: Fixing the big roads," in which they coined the phrase "road diet."

"(A road diet) may sound counterintuitive," Burden said, "but if you put on 25 pounds you won't be healthier - it's the same concept for a street."

Road diets shouldn't be used on streets with an average daily traffic of 20,000 or more because traffic congestion could increase to the point of diverting traffic to alternative routes, said Burden.

According to Burden's non-profit, traffic flow has increased by about 1,000 vehicles per day in areas of Seattle where road diets were implemented.

"Seattle was the first city in the country to start implementing road diets aggressively," said Burden, noting that Seattle has used the method more than any other city in the country.

Other road diet benefits include a 5 percent improvement in safety and up to an 80 percent reduction in crashes, Burden said.

But some think the city should move cautiously and wait to see how major developments in the area will impact pedestrian and traffic patterns.

Rebekah Schilperoort can be reached at 783.1244 or rebekahs@ballardnewstribune.com