I-35/NE 36th Street Interchange

The City of Ankeny is a member of the Des Moines Area Metropolitan Planning Organization (MPO). Because of burgeoning traffic resulting from growth in Ankeny, several recent MPO studies had called for improvements to the E. 1st Street interchange. Moreover, these studies concluded that an additional interchange was needed at or near NE 36th Street, two miles north of E. 1st Street. Therefore, the City of Ankeny retained HR Green to complete an Interchange Justification Report (IJR).

A major challenge in gaining Interstate access approval is balancing the need for local access with the equally important need to preserve the integrity of the Interstate system’s operations. HR Green sought collaboration among these interested parties to ensure that their differing objectives were respected.

HR Green, in cooperation with the Des Moines Area MPO and the Iowa DOT, successfully demonstrated that the proposed improvements would not have a significant adverse impact on the safety and operation of the Interstate, while meeting the objectives for local and regional travel.

HR Green also provided NEPA environmental services for the project. The project studied approximately four miles of I-35 and two miles of urban arterial street. Prominent land use features include an existing rest area, potential impacts to the Otter Creek Golf Course, which was classified as a Section 4(f) resource with potential 6(f) elements, wetland and potential stream mitigation associated with nearby Four-Mile Creek and its tributaries, and potential noise impacts to residential areas.