I-280/Winchester Boulevard Interchange Improvements Project
SVS has years of experience helping organizations and government entities find solutions to problems with roads and bridges. SVS has worked with VTA to add value to the road and bridge projects throughout the years. When VTA approached us to consider a value engineering workshop for their I-280/Winchester Interchange, SVS was ready.
The project modifies the existing I-280/Winchester Boulevard interchange by constructing a new off-ramp from northbound I-280 to the intersection of Tisch Way and Hatton Street and a new direct connector ramp from northbound SR17 to northbound I-280. A new bike/pedestrian overcrossing at Monroe Street as well as a bridge widening on Winchester Boulevard are proposed to improve bicycle and pedestrian access across I-280.
The purpose of this project is to improve traffic operations on local streets, bicycle and pedestrian access, transit connectivity, and access from northbound I-280 to the project area. The proposed improvements, such as a flyover bridge connection and tunnel, would result in additional increase in the net impervious areas within the project limits.
The Value Team maintained a delicate balance between validating the existing design and challenging the current thinking. Staying within the parameters, the Value Team offered several alternatives that address the exit ramp, facilitate construction, and separate traffic. To create an exit ramp, the Value Team recommended raising the T-line profile and bridging over ramps in lieu of a tunnel, reducing shoulder widths on the flyover bridge, reducing the diameter of piles where feasible, and replacing bridge spans with embankment. Two significant geometrics alternatives were proposed to create an exit from I-280 NB without impacting the existing loop ramp and thereby eliminating the need for the system-to-system flyover and tunnel exit ramp. One option created an exit ramp flyover, and the other used a series of undercrossing. Both options had the ability to save 20% of the total project’s capital cost. To facilitate construction, the Value Team developed alternatives to simplify column bents, realign ramps, and remove the existing pedestrian overcrossing (POC) obstacle during construction. To separate vehicle traffic from ped/bike traffic, the Value Team recommended reducing the width of the new POC, reducing the width of the Winchester Boulevard widening, creating dedicated POCs at Winchester Boulevard, and eliminating the new POC in the park.
The Value Team identified opportunities and developed Value Alternatives which resulted in a potential cost avoidance of 31% of the project costs over the life of the project while still maintaining the intended functional performance of the project.