A project designed to make a dangerous highway intersection safer is now underway in Black Hawk County.

The Iowa Department of Transportation (IDOT) is constructing an overpass and interchange for County Road C-57 -- also known as Cedar-Wapsi Road -- at U.S. Highway 218 between Cedar Falls and Janesville. The $19-million project is expected to be finished in the fall of 2016.

Construction on the diamond interchange officially begins today (Wednesday, April 1, 2015) with the closure of Cedar-Wapsi Road on both sides of U.S. 218. IDOT officials are encouraging motorists to follow the paved detour route that's designated for Cedar-Wapsi Road. Four-lane Highway 218 is expected to remain open throughout the construction process.

Workers have spent the past few weeks relocating railroad tracks and removing trees from the construction zone. Over the next 18 to 20 months, two new bridges will be built for Cedar-Wapsi Road -- one crossing over U.S Highway 218 and another above the relocated railroad tracks. A frontage road will also be built to access some businesses near the intersection.

Talk of building an interchange for Cedar-Wapsi Road at U.S Highway 218 began in 2003 when meetings were held with local jurisdictions and law enforcement agencies. In 2005, the IDOT initiated a safety improvement study and began developing options for access control of U.S. 218 for the corridor between Cedar Falls and Waverly.

Photo By: Elwin Huffman - Waterloo Broadcasting

The volume of traffic using that 15-mile stretch of highway has steadily increased and operational issues have developed since U.S. 218 opened as a four-lane expressway in 1995. The existing at-grade intersection at Cedar-Wapsi Road has been a common place for severe accidents and fatalities the past 20 years.

Temporary improvements have been made to the intersection over time, but continued traffic growth is expected throughout the corridor in the future. The IDOT estimates 20,000 vehicles pass through the U.S. 218/Cedar-Wapsi Road intersection everyday. That figure is projected to increase to nearly 29,000 by 2037.

When the project is finished, access to U.S. Highway 218 between Cedar Falls and Janesville would be by interchange only. According to project plans, the Mount Vernon, Bennington and Gresham roads intersections at U.S. 218 will be permanently closed and the median crossovers would be removed.

IDOT officials are asking motorists to use extra caution when driving through the construction zone.