Erik Halstead: Highway 18/223 junction ill-suited for roundabout

##Eric Halstead

About the writer: West Salem resident Erik Halstead, a graduate of McMinnville High School, serves as a senior field collections supervisor with Portland General Electric. He previously held posts in logistics, customer service and management analysis with several firms, including AT&T, PacifiCorp and UPS. Before moving to Salem, he served four years on the Transportation Advisory Committee in Tigard.

Last week, Lisa McCracken asked, “What’s the American aversion to roundabouts?”

Roundabouts are just one of many transportation tools to help traffic move. The problem in America is that roundabouts are used as a “traffic calming” device, whereas in Europe and elsewhere in the world, they are as a “traffic throughput” device — that is, they are built to efficiently move traffic without significantly slowing or stopping traffic.

Roundabouts work great when you have multiple entry and exit points with relatively consistent speeds and traffic volumes.

Hence, they work on Hill Road, where most of the traffic is already doing 25-35 miles per hour and there’s an equal distribution of traffic on the intersecting roads. They work in Bend for the same reason.

Now, take Highways 18 and 233, the Lafayette Highway. There you have a major east-west thoroughfare averaging 20,000 vehicles a day, but carrying significantly more on major summer and holiday weekends, intersecting with a secondary north-south route carrying fewer than 4,000 vehicles a day.

The overwhelming majority of the traffic is going east-west.

North-south traffic on Lafayette Highway is accustomed to stopping, but east-west traffic on Highway 18 is not. The 55 mph traffic on 18 will be forced to slam on the brakes for a 20 mph curve, then be tempted to floor it to getting back up to highway speed.

A roundabout would negatively affect the flow on Highway 18, and the volume of that traffic would hinder Lafayette Highway traffic from proceeding into the roundabout. That would serve to create long traffic jams on 18, negating any benefit it might otherwise have.

What’s more, traffic might divert back onto 99W, increasing the flow through downtown Lafayette, where the Oregon Department of Transportation has spent a lot of money on pedestrian safety.

Insisting on a roundabout is another example of value-engineering a project when this intersection rightfully should be served by a grade-separated interchange.

McCracken suggests an overpass would be at risk of collapse during an earthquake.

I have to wonder how she sleeps at night knowing how many bridges the area already has — Highway 99W over the North Yamhill River, Three Mile Lane and Highway 18 over the South Yamhill River and Highway 18 over the Yamhill River in Dayton, not to mention the Highway 18 interchanges on either side of McMinnville, the 99W overpass taking traffic south to Amity and the South Yamhill River span at Whiteson. If bridges are such a problem, why did we just build a new one for Three Mile Lane?

I know all too well that the Highway 18/233 intersection needs fixing, but a roundabout is a foolishly wrong answer. Build the damn interchange and save lives that way.