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Circular Reasoning

Analyzing the proposed roundabout along U.S. Highway 2 at Dern/Springcreek roads

By Dave Skinner

Sometimes I find myself struggling with a topic. Lucky me, on Wednesday the 13th I went down to the Hampton Inn for Montana Department of Transportation’s open house concerning one of 17 Missoula District highway projects: Dern/Springcreek.

Road intersection improvements. Boy, now I’ve got a topic!

In case you don’t know where Dern/Springcreek is, it’s the yellow flasher intersection west of Kalispell, down in the hole between the truck scale and the top of Hartt Hill. It’s terrible, with no safe left turns or crossings. When I need to get to U.S. 2 West, I use either the bypass or West Valley drive.

How bad is it, really? The traffic study on MDT’s website shows the most dangerous moves and over three-fourths of the total wrecks involve the minority of drivers who try to turn left on or off, or worse, try to cross U.S. 2.

And making those lefts and scooting is hard. For peak-hour morning lefts (Springhill to town), the delay was 45.5 seconds, in the evening, 34.8 seconds, still bad. Want to jump straight across? 41 seconds.

What about turning left off the highway either north or south? Roughly eight to nine seconds “delay” (stopped in the traffic lane), a long time to sit, especially when those behind you can only see four seconds ahead! From the report, 29 percent of wrecks were rear-enders, with 79 percent being someone trying to turn left up Springhill.

Think that’s bad? Consider the projection if nothing is done and trends in traffic increase keep on for 20 years: Try 581 seconds (9 minutes, 51 seconds) if you’re still stupid enough to want to turn left toward town from Springhill in the morning, or dash across both lanes, which is the category for over 65 percent of the wrecks, including 23 “right-angle” or T-bone hits.

So, what’s the solution? A light? Left turn lanes on 2? Cutting off Dern to stop crossings, which statistically present the worst odds? Still doesn’t fix lefts to and from Springhill.

How about rights only, emergency-vehicle lefts only, no crossing, have people use, um, Two/Three Mile/West Valley/bypass, which smart people already do? Not considered.

The winner? Roundabout, “selected as the safest alternative.” Safest, maybe, but appropriate?  For one thing, the nearest, and totally bogus, U.S. 2 roundabout is on the other side of Stevens Pass in Washington. The other way, there’s none clear to Minot. For good reason – U.S. 2 is a transcontinental artery, not a back road like south Kalispell Bypass!

The speed limit through the intersection is now 60 miles per hour. What MDT wants is a round, round, roundabout with all vehicles having equal rights. Should they? Nope. Peak traffic shows 2,168 vehicles going straight on 2, with another 367 turning. Springhill contributes 314 entries, with 48 jumps. Dern: 73 entries, 45 dangerous jumps. So, we’re imposing speed and direction changes on our most-important traffic flow of 2,168 vehicles to favor 754 that would be turning and slowing anyway? Sorry, but that’s a poor trade.

I also was told that most vehicles will traverse the roundabout at 20-25 MPH, or, as MDT writes regarding most roundabouts, “slow to 15 to 20 mph” and wind back up to 60. But don’t forget trucks (about one in 20 of all vehicles) in both directions will have to brake down a still-steep 4 percent grade (albeit to a new “low point” an important seven feet higher than now), do the hokey-pokey of three separate turn phases, then grind up the opposite hill in a lower gear in a no-passing zone. Can you see the happy commuters backed up to Batavia or the bypass? Happy, and so, so safe.

So, here’s a little circular reasoning: Let’s extend the 45 speed limit from Hartt Hill to the hilltop west of Springcreek/Dern. Instead of a “round” about, make an “ovalbout” with the approaches stretched along east and west so straight runners on 2 face a single gentle curve appropriate for 45. I’d keep the turn circle, but entries would be controlled by stop signs, with drivers only needing to deal with traffic from one direction at a time.