- Roadway Design
- Structural Design
- Drainage Design
- Plaza Electrical Engineering
- Communications System Design
- Lighting Design
- ITS Design
- Utility Coordination
SINGH, as Prime Consultant, was responsible for the complete reconstruction of the bridge structure carrying 159th Street (US 6) over the Tri-State Tollway (Bridge 125) and the reconstruction of the interchange loop ramps. Due to the bridge condition, a complete reconstruction was required with Construction NTP to occur in 2018 to avoid costly maintenance and repairs. SINGH completed the design on an accelerated schedule of nine (9) months to meet a construction letting of December 2017.
Designed as a 2-span continuous composite bridge supported by 54” PPC IL beams on semi- integral abutments and one pier; the structure length was extended to allow for the widening of the collector-distributor road shoulders under the bridge structure. 159th Street is an IDOT roadway, identified as a Strategic Regional Arterial (SRA) route and improvements were design to meet SRA criteria. The design maintained two lanes of traffic in each direction with an auxiliary lane in the eastbound and westbound direction with a raised median. Design incorporated a shared used path and protected 7’ sidewalk in compliance with IDOT Complete Streets policy.
The approaches to the bridge along with the loop ramps were replaced to tie into the new bridge, affecting horizontal and vertical locations. The existing loop ramps within the interchange had sub-standard curve radii that did not meet Illinois Tollway requirements for 30 MPH design speed. SINGH provided contract documents for the reconstructed pavement as well as the installation of new inlets along each bridge approach and new underdrains and outfalls.
Project scope also included: drainage design, maintenance of traffic, pavement marking and signage, landscaping and erosion control, barrier warrant analysis, Plaza 40 electrical and communication systems design, lighting system removal and replacement LED lighting system, ITS device removal and relocation, underground ITS infrastructure and fiber optic removal and relocation, pedestrian accommodations on 159th Street, overhead sign structure replacement, and utility coordination.
SINGH coordinated and managed the development of the contract documents for structural services provided by a subconsultant.