Intermediate safety improvement scaled back at Springville intersection

Safety improvements planned as an intermediate step at the intersection of Highway 151 and Springville Road have been scaled back because of possible conflicts with heavy trucks.

The DOT decided recently not to build a raised center medians that would create a  protected stop area for northbound or southbound vehicles to stop after crossing one set of lanes, according to Cathy Cutler, transportation planner for DOT District 6.

Potential problems with the raised median became evident from the DOT's experiences with a similar median on Highway 330 in central Iowa, Cutler said. Large trucks attempting to turn at the intersection often went over the raised median and repeatedly damaged or destroyed stop signs on the center islands, she said.

The DOT believes many accidents at the intersection will be avoided if motorists stop in the center of the intersection after crossing the first two lanes of travel. Motorists are encouraged to stop on the center island even without the raised median, Cutler noted.

Shoulder-paving work intended to make the interchange safer went ahead last week without the median islands. The project paved the portion of the inside and outside gravel shoulders.

The partially paved shoulder will reduce problems with the erosion of the gravel shoulder when heavy trucks drift off the paved portion, leaving a drop-off at the edge of the pavement, Cutler said.

The DOT is also installing a portable camera to study traffic at the intersection in order to better understand what is causing accidents, Cutler said.

A series of major crashes at the intersection have prompted the Iowa Department of Transportation to study modifications or redesign of the at-grade intersection, where many motorists turn off Highway 151 going to and from Springville or Mount Vernon

A proposal to modify the intersection using a J-turn design ran into local opposition last year. Residents said it might interfere with truck movements, and they did not like the fact that it would block northbound traffic on Springville Road from crossing the intersection.

Some residents favor construction of a overpass. The DOT has begun studying that concept, according to District Engineer Jim Schnoebelen. He said the DOT currently has no funding for an interchange included in its five year program.

The process to obtain environmental approvals, design, right of way, and to build an interchange can take several years, Schnoebelen said, so a decision was made to make interim improvements.