Located in southwest Ohio, the I-71 and Western Row Road partial interchange was constructed in the 1970’s with the primary purpose to provide access for visitors coming north from Cincinnati on I-71 to Kings Island Amusement Park’s parking lots.   The remaining adjacent land use was primarily farmland and undeveloped woodlands.  Since then, southwest Warren County has experienced explosive growth.  Both Deerfield Township and the City of Mason blossomed into sprawling residential subdivisions and a world class business park developed adjacent to I-71, specializing in high-tech and healthcare industries.

The Warren County Transportation Improvement District (WCTID), in conjunction with the Ohio Department of Transportation (ODOT), Ohio Kentucky Indiana Regional Council of Governments (OKI), the City of Mason and Deerfield Township, coordinated efforts to reimagine the

Addressing Safety was First Priority

First the project had to address the safety and congestion issues that already plagued the area.  In most cases the safety issues could be directly attributed to the heavy congestion along Western Row Road and Columbia Road.  The most significant issue was the spacing of the I-71 northbound ramp / Kings Island Drive signalized intersection with the Columbia Road signalized intersection along Western Row Road.  Numerous “fixes” had been applied to improve the condition, but the fact that the two signals were only 400 feet apart was the root cause.  The other safety issue on Western Row resulting in higher than state average crash rates was due to a 90-degree curve just east of Columbia Road.

Planning to Enhance Economic Development

From the outset of the project, Stantec worked with the WCTID and the City of Mason to develop a plan that addressed current safety concerns and peak traffic demands, while also enhancing economic development opportunities in the area.

Initial work that identified the need to bring the missing movements to the existing partial interchange was in the Southwest Warren County Transportation Major Investment Study (MIS) in 2005. That report projected a 635% increase in vehicle hours for the 2030 design year as compared to a 323% increase for the remainder of the OKI region.

In 2011, the project team began work to identify a preferred alternative from the three alternatives advanced from the MIS.  This process involved multiple stakeholder meetings within the business community, coordination with the City of Mason’s Economic Development Director and a public information meeting.  The resulting preferred alternative changed the ramp terminals from Western Row Road to Innovation Way and brought together the business community as a strong supporter of the project.

Stantec provided preliminary engineering with the development of various design alternatives and prepared an Interchange Modification Study for the preferred alternative.  Traffic simulation models were created for each of the alternatives with TransModeler to better understand where congestion was being relieved and what side effects might result from various connections.  The project team also completed all required environmental field studies, ecological base studies, hazardous material screenings, cultural resource investigations, and prepared a Level 2 Categorical Exclusion Environmental Document and all necessary waterway permits.

Interchange Design and Phasing

The project was completed in two phases.  The first phase relocated Columbia Road around existing retail businesses to provide adequate intersection spacing along Western Row Road between the I-71 exit ramp terminal / Kings Island Drive and the new the Columbia Road intersection.  This change alone made significant improvements to safety and congestion in the area.  Additionally, the I-71 northbound exit ramp was widened, the employee entrance to Kings Island was relocated and a nearby 90-degree bend in Western Row was softened to provide increased sight distance. Relocating Columbia Road required the extension of a 150-in. diameter corrugated metal pipe culvert at both the inlet and outlet. The depth of the fill over the end of the existing culvert and the extension at the outlet is approximately 25 feet. The supporting soils were not strong enough to support the total fill of 40 feet or the new full-height headwalls at the inlet and outlet. Therefore, stone columns were utilized to improve the bearing capacity of the soil. In addition, there were concerns about settlement of the ground supporting the end of the existing culvert and the possible creation of a low point in the culvert at the tie-in to the extension. To reduce the amount of settlement, a 15-foot depth of EPS Geofoam was used in the fill above the end of the existing culvert to reduce the weight of the embankment on the culvert.

Aesthetics were important in this phase of the project and were incorporated into several aspects of the project, including the retaining wall required to support the property of an adjacent business. The concrete face of the soldier pile wall utilized alternating formliner patterns with “frames” defining each pattern and the top of the wall.

The second phase added the missing I-71 southbound exit ramp and I-71 northbound entrance ramp.  To best serve the business community, the exit ramp ties directly to Innovation Way which parallels I-71 to the west and intersects with Western Row Road.  A new southbound entrance ramp from Innovation Way was also added.  Innovation Way was widened from two to four thru-lanes and turn lane adjustments were made along Western Row Road.  Additionally, an auxiliary lane was added on I-71 in both directions between Western Row Road and the SR-741 interchange.

To accommodate the new southbound exit ramp, the existing I-71 four-span concrete slab bridge over Western Row Road was widened to the west.  To avoid vibrations from pile driving interfering with sensitive testing equipment in a nearby firm, drilled shafts to bedrock were utilized to support the pier extensions and pre-drilled holes were used for the steel piles to bedrock supporting the abutment extensions. To accommodate the new northbound entrance ramp, a new four-span concrete slab bridge was constructed over Western Row Road to the east of the existing bridge. The outside face of the parapet on this bridge and the widened portion of the existing bridge were enhanced to show the City of Mason’s name and logo, welcoming visitors to the region. Three-dimensional letters and images mounted to the concrete face were utilized for the name and the logo.

Project Coordination

During construction it was essential that the public and key stakeholders were aware of traffic restrictions and that the Contractor worked around peak recreational events.  Two of the project neighbors were the Kings Island Amusement Park which hosts over 3.5 million visitors a year and the Western & Southern Open Men’s and Women’s ATP Tennis Tournament at the Linder Family Tennis Center held in August with nearly 200,000 spectators over the week-long event.   The maintenance of traffic plans were developed to make sure that lane closures and restrictions were minimized during the tournament week and that signage was clear for out of town visitors throughout the project duration.

The Project Team

Stantec served as the prime consultant on this project, with an excellent team of sub-consultants who helped make this project a success.  Other team members were Bayer Becker (traffic counts, signal design and landscaping design), Terracon (geotechnical services, Aerial Technologies (aerial mapping), SHA Engineering, LLC (assisted with traffic analysis), AMEC (ESA investigations and public involvement support), and Gray & Pape (cultural resources investigations).  For construction John R. Jurgensen Company was the general contractor for both project phases.

Award Recognition

The project was recognized by the Triko Valley Section of ASHE with the 2020 Donald C. Schramm Transportation Improvement Award in the over $5 million category.  The American Council of Engineering Companies (ACEC) Ohio also recognized the project with an Honor Award as part of the 2020 Engineering Excellence Awards.

The improvements at Western Row Road’s interchange with I-71 helped to unlock more of the potential of southwest Warren County by alleviating congestion and safety concerns and providing increased access to the interstate from all directions.  This allowed the interchange to better serve the residents, businesses and visitors to the area and will allow for the continued economic growth opportunities within the region