Security State Bank probably thought it had a swell deal with a high-visibility spot on four-lane US 151 at the new main entrance to Springville. A building opened in the northwest corner of the intersection with County Road X20 in 2005.
But with the completion of the four-lane to Dubuque, traffic on 151 increased substantially. For more than a decade, the intersection has been on the state’s list of most dangerous. A KCRG story from 2017 about one of the crashes said there had been 34 in seven years.
Nearly a decade ago, the DOT wanted to set up a J-turn — you may remember this term from when it was a possibility at the IA 330/US 65 intersection, and again when it was a possibility at the US 30/218 intersection. Indiana just started using it; it’s a close cousin of the “Michigan Left” except that a J-turn allows left turns from the dominant road. But it means that traffic from the intersecting road has to turn right, cut through two lanes of traffic moving at high speeds, and then merge from the left into other traffic moving at high speed. The technique has not appeared in Iowa yet, and every time it’s proposed it’s met with strong opposition.
Now, eight years after the state presented 16 alternatives for the 151/X20 intersection at Springville, the state … has completed the environmental assessment on an interchange. Three of the dismissed alternatives use a “parclo” setup which involves a loop ramp for northbound X20 to southbound (westbound) 151. But the DOT’s preferred option is a diamond interchange with that ramp going right through the existing Security State Bank building. The Casey’s next door would remain intact (or so I interpret).
There will be a meeting about the interchange, with a formal presentation, on March 12 at St. Isidore Catholic Church, which is right by the intersection.
The Springville intersection is likely the most important one between Marion and Dubuque that didn’t get grade-separation, because that part of 151 was four-laned earlier. But the situation there isn’t tenable anymore, and an interchange needs to happen.