They show demolished cars flipped on their backs, a dramatic picture certain to startle drivers on Rainier Avenue South. Billboards depicting the graphic...

They show demolished cars flipped on their backs, a dramatic picture certain to startle drivers on Rainier Avenue South.

Billboards depicting the graphic images are going up on the street in hopes of encouraging drivers to slow down.

“More than 600 crashes happened along the Rainier corridor last year,” said Grace Crunican, with the Seattle Department of Transportation, which is working with the Washington Traffic Safety Commission to install the billboards. “We hope the images resonate; we want people to slow down.”

Last year there were 643 crashes on a 7.5-mile stretch of Rainier Avenue South, between Dearborn Street and Renton.

As a comparison, the eight miles on Aurora Avenue North from the Battery Street Tunnel to North 145th Street saw 434 crashes last year.

As for accidents involving pedestrians who were jaywalking, there were 61 on Rainier Avenue over the past five years, compared with 33 on Aurora.

The messages on the billboards — “Slow down: crashes cost” and “Slow down: 643 crashes on Rainier Avenue last year” — came from two focus groups, one with Vietnamese speakers and the other with English speakers. Participants were male drivers between 20 and 45.

The billboards are being financed by the Traffic Safety Commission and cost about $7,000.

The first was installed last week on Rainier Avenue South just north of South Walter Street. It will remain in place for four weeks and then move to three other locations: Brandon Street, 42nd Avenue South and South Thistle Street.

The campaign will last 16 weeks and is part of Mayor Greg Nickels’ pedestrian-safety campaign.

Susan Gilmore: 206-464-2054 or sgilmore@seattletimes.com