Tuesday, October 18, 2016

New I-205 ramps in Vancouver save time, improve safety

By Tamara Greenwell

Thousands of travelers in east Vancouver are shaving time off their daily commute now that the Interstate 205 Northeast 18th Street Interchange is open. While the changes are taking some getting used to, early indications are that drivers are not only adjusting well, they're already seeing benefits.

A drone's-eye view of the new I-205 interchange.

A roundabout way to keep things moving
Roundabouts. They're designed to make intersections safer and more efficient and so far we're seeing that in east Vancouver. For the first time ever, travelers can access I-205 from Northeast 18th Street. The 15 mph speed limit might seem like it slows you down but it actually allows folks to safely navigate the roundabout while keeping all traffic moving through the area. Unlike intersections with traffic signals, drivers don't have to wait for a light to change to get through, keeping traffic flowing.

The new interchange is drawing many commuters who otherwise would've used Southeast Mill Plain Boulevard or State Route 500 to access I-205. Having a new interstate on-ramp gives drivers more options, breaking up that three-mile stretch, distributing traffic around the system. That means fewer delays for the thousands of drivers who use the highway and surface streets every day.

So how does it work?
The new on-ramp from Northeast 18th Street is separated from the newly extended southbound off-ramp to Southeast Mill Plain Boulevard. We call this separation of ramps “braided ramps.” We use them in areas with lots of traffic and not a lot of room. By separating the ramps, we increase the amount of roadway surface and give drivers more room to merge without weaving into each other. The end result: a drop in both crashes and delays along the corridor.

Time-lapse of crews building the I-205 NE 18th Street on-ramp.

Meanwhile, at 112th Avenue
The 112th Avenue Connector project, the companion project to the 18th Street Interchange completed in 2010, has proven to help keep traffic moving in east Vancouver. Drivers on northbound I-205 have direct access to Northeast 112th Avenue, which means bypassing the often congested intersection at Mill Plain Boulevard and Chkalov Drive.

A traffic study shows drivers using the new ramp cut nearly two minutes off their afternoon commute through the area. While two minutes doesn't sound like much, it adds up! Take a look at the numbers.

  • 10 minutes a week
  • 480 minutes a year
  • 8 hours of drive time saved in one year!
We all know it takes time to change habits, so it's too soon to tell the full impact of the new 18th Street on- and off-ramps. We're doing a traffic study now and we'll be sure to update you when we get the results.