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  • Location: Columbus, Ohio

To untie the traffic tangle where State Route 315, I-70 and I-71 meet in downtown Columbus, Ohio, B&N led a study to identify a new interchange design that will improve operations, minimize project costs, require less right-of-way and reduce the impact on businesses.

The interchange study is part of the large-scale, multi-billion dollar I-70/I-71 Columbus Crossroads project. The 315/70/71 interchange is a key access point into Columbus where two major interstates and a limited access freeway converge.

The client, the Ohio Department of Transportation (ODOT), determined that a previously proposed interchange alternative was too costly and did not allow for phased construction, which is more affordable because construction costs can be spread out over a longer period of time. ODOT also believed the original alternative required too much right-of-way acquisition.

Due to the firm’s knowledge of this interchange and expertise studying complex interchanges, B&N was selected to reevaluate the previously proposed alternative and provide new alternatives for consideration.

The B&N team was tasked with finding a new interchange design alternative that met the following goals:

  • Improve safety
  • Increase roadway capacity
  • Reduce the previously estimated project costs
  • Improve sustainability by reusing more existing infrastructure
  • Reduce the amount of required right-of-way acquisition and project footprint
  • Minimize the impact to businesses and citizens
  • Develop a phased construction strategy

Workshop Process

B&N led a workshop process to analyze and identify potential interchange design alternatives using evaluation criteria that were developed in collaboration with ODOT. The criteria were used to measure the performance of each proposed alternative. This included safety, route continuity, residential and business impacts, access impacts, adherence to design standards, traffic operations, and additional criteria that could be used to compare each alternative.

Two workshops were held over a four-month period. Project stakeholders and decision makers, including ODOT, the City of Columbus, the Federal Highway Administration (FHWA), and the consultant team provided feedback and consent for alternatives selection.

During the first workshop, participants reviewed eight alternatives with base-level traffic analysis to allow for efficient review and elimination of options. Participants narrowed alternative options down to two during this first workshop.

A higher level of traffic analysis and engineering detail was completed on the remaining two interchange alternatives, which were presented during the second workshop.

The second workshop lasted two days. At the conclusion of day one, B&N utilized an overnight team to update and prepare new drawings. Working overnight allowed B&N to present updated alternatives on the second day that reflected all comments and discussions from the first day. This strategy greatly improved the efficiency of the workshop. At the conclusion of the second workshop, a single recommended interchange alternative was chosen, completing the workshop process and the preferred alternative identification in just four months.

B&N then assisted ODOT by developing presentations for and participating in more than 10 individual stakeholder meetings and two general public meetings. During the meetings, B&N presented the newly identified preferred alternative for the interchange. With this level of outreach and communication, the team secured buy-in from area stakeholders.


In the final I-70/I-71 West Interchange Reevaluation report that documented the process and proposed alternatives, B&N engineers outlined a five-phase interchange solution that ODOT is pursuing. The options outlined are expected to satisfy the project goals and save an estimated $400 million in construction costs.

B&N continues to assist ODOT with plans for improving this heavily traveled interchange. Upon completion of the I-70/I-71 West Interchange Reevaluation, B&N was retained by ODOT to monitor the design of the first two projects that were identified in the study. This oversight is intended to ensure that those projects are in compliance with future projects identified in the study.