The Keystone Parkway project began as a conceptual design of a four-lane expressway. The project was designed to improve connectivity across the city for all modes of transportation, including motorized vehicles, bicyclists and pedestrians. The planning process included evaluating the lowering portions of the existing Keystone Avenue, and determining the effects the project would have on adjacent properties.
The City of Carmel, Indiana, has been nationally recognized for its roundabout program. Utilizing low impact and sustainable principles, the design team developed an innovative double teardrop roundabout interchange solution. This solution minimized the interchange footprint, reduced traffic idling and congestion, eliminated the need for signals, restored original Photos provided by American Structurepoint, hydrology, preserved countless buildings, and dramatically reduced the project timeline.
The Keystone Parkway project included the reconstruction of six, at-grade, signalized intersections to grade separated, double teardrop interchanges. Keystone Avenue was to be lowered up to 20 feet, enabling the cross streets to remain at or near existing grade, as well as reducing the encroachment onto adjoining properties. All roadways included new pavement, curbs, gutters, multi-use paths and an enclosed storm sewer system.
The large cuts along Keystone Avenue provided an additional challenge with groundwater. To address this, American Structurepoint Inc. designed a complex subsurface drainage system incorporating Contech A-2000TM PVC storm sewer pipe. A-2000 provided the City with an opportunity to gain cost savings while also maintaining higher strength and reduced deflection potential over the reinforced concrete pipe (RCP) alternative.
“Our long-term relationship with Contech provided a level of comfort when choosing this solution” said Craig Parks, Project Development Director with American Structurepoint Inc. ”These innovative, cost-saving design solutions will help us provide an excellent final product to our clients”