Getting moving on road data

RTC report ranks the most congested corridors in county

By Eric Florip, Columbian transportation & environment reporter



When a local transportation report ranked a section of Vancouver’s Northeast 18th Street the most-crowded corridor in Clark County — comparing its usage to its capacity — this summer, it came as no surprise to city planning manager Matt Ransom.

Construction crews began widening the thoroughfare in October, the $10.25 million first phase of a project designed to solve that very problem. But Northeast 18th had been known as a trouble spot for years, and city planners had long since zeroed in on it.

“For me, this project started, like, nine years ago,” said Ransom, a city planning manager.


Most-crowded corridors in Clark County, volume to capacity:

Northeast 18th Street, 112th Avenue to 162nd Avenue (afternoon): 111 percent.

State Highway 14, I-205 to 164th Avenue (afternoon): 100 percent.

I-205, North Airport Way (Portland) to Highway 500 (afternoon): 92 percent.

Lowest-speed corridors at peak travel times:

Northeast 112th Avenue, Mill Plain Boulevard to state Highway 500 (afternoon): 15 mph.

I-5, Main Street to Jantzen Beach in Portland (morning): 16 mph.

Northeast Fourth Plain Boulevard, I-5 to Northeast Andresen Road (afternoon): 19 mph.

SOURCE: Southwest Washington Regional Transportation Council

The Southwest Washington Regional Transportation Council’s Congestion Management Process offers a regular look at the county’s most crowded and slowest corridors. That information is used to identify the worst spots and track changes from year to year. Annual reports also give local officials a stronger case when they seek federal and state money for projects to address them, said Jack Burkman, a Vancouver City Council member and RTC chair.

“It points out that where we’re putting our money is where we have highest need,” Burkman said. “Here’s a documented need. … We’re not guessing. We’ve tracked it.”

The RTC’s 2010 report — released this summer, and mentioned by Burkman at a recent Vancouver council meeting — puts hard numbers on some well-known trouble spots.

The most-packed corridor: That would be Northeast 18th Street between Northeast 112th and 162nd avenues. It operates at 111 percent of capacity during peak afternoon hours — the highest of any stretch in the county.

The slowest: That’s Northeast 112th Avenue, from Mill Plain Boulevard to state Highway 500. During peak travel hours in the afternoon, cars crawl along at an average speed of 15 mph.

The farthest off the speed limit: Interstate 5 from Main Street to Portland’s Jantzen beach area moves traffic at just 16 mph during busy morning hours. That’s only 29 percent of the speed limit, according to the report.

Those results aren’t likely to shock any regular commuter. What changes, Burkman said, is the simply bad trends that get worse year to year.

“Until you make an investment, they continue to be problem areas,” he said.

RTC reports have identified plenty of other transit troubles that are now the sites of major construction projects. The Washington State Department of Transportation is rebuilding the Salmon Creek Interchange of I-5 and I-205, and widening state Highway 14 east of Vancouver. City crews are tackling the Northeast 18th Street project and rebuilding the state Highway 500/St. Johns Boulevard interchange, among others.

Jams of every flavor

Not every problem holds an easy solution. On Mill Plain east of I-205, for example, no single construction project will fix another one of the county’s slowest-moving corridors, Burkman said. And on Fourth Plain, planners are trying to balance transit needs with the worries of an eclectic group of businesses and residents, he said. C-Tran has recently focused on Fourth Plain as a possible candidate for new high-capacity transit options.

The city of Vancouver has also looked at revamping the intersection of Fourth Plain and Northeast Andresen Road, Ransom said.

The RTC’s regular congestion monitoring comes through near-constant collaboration with other local agencies. That means “daily, weekly, monthly” contact with the city, Ransom said. For the Washington State Department of Transportation, the information is “one important piece” of the agency’s long-term investment plans, said spokeswoman Abbi Russell.

Like other agencies that contribute to the RTC’s work, WSDOT didn’t find anything unexpected in this summer’s report, said regional planning manager Sharon Zimmerman. That’s particularly true of the I-5 southbound bottleneck approaching the Interstate Bridge.

“That’s definitely an area we’re aware of for congestion,” Russell said.

Eric Florip: 360-735-4541 or