Premier developed the design from 30% to 100% plans, specifications and estimates for Segment 6 of the SR 303L (Estrella Freeway). This 3.5-mile segment begins at Waddell Road on the south end, and ends at Mountain View Boulevard on the north end. The SR303L mainline consists of three general purpose (GP) lanes in each direction separated by an open median with cable barrier. The open median accommodates the future construction of a concrete median barrier plus a new GP and high occupancy vehicle (HOV) lane in each direction. This project includes two traffic service interchanges (TI) at Greenway Road and Bell Road, both of which are classified as City of Surprise major arterial streets.
Greenway Road improvements included horizontally realigning the roadway to the south, partially elevating the roadway as it crosses over the SR303L mainline, and a new underpass bridge. Improvements included three through lanes in each direction separated by a raised median and dual left turn lanes and single right turn lanes at the TI, which is a Compact Diamond Interchange.
Bell Road crossroad improvements, new underpass bridge, and utility bridge were constructed as part of the Statewide Transportation Acceleration Needs (STAN) projects. This project included TI ramps, traffic signals and connections to be fully functional as a traffic service interchange with SR303L. The Bell Road TI is a Single Point Urban Interchange (SPUI). The SR303L mainline is partially depressed under Greenway Road, fully depressed under Bell Road, returning to grade slightly north of Bell Road, and continuing at grade matching into the existing SR303L at Mountain View Boulevard. The northbound SR303L transitions from a three-lane freeway section to the existing one-lane roadway just south of Mountain View Boulevard. Similarly, the southbound SR303L transitions from the existing one-lane roadway to a three-lane freeway section.
In addition to the new two-span cast-in-place post-tensioned concrete box girder underpass bridge, we designed a concrete lined open channel which was constructed along the west side of SR303L and conveys the offsite and onsite freeway drainage to the south. This channel connects to the drainage system of the adjacent project at the south end. The project also included numerous channel transition structures, sound walls and retaining walls at various locations between Greenway Road and Mountain View Boulevard.