I-35/US-69 Upgrade
Project Overview
MoDOT selected GBA for design improvements along the I-35 corridor between Vivion Road and Pleasant Valley Road. Prior to GBA’s engagement, MoDOT staff had evaluated dozens of interchange concepts. GBA guided MoDOT through a process to determine the most feasible interchange option – an offset diamond interchange with safety features. GBA developed an innovative offset diamond interchange to improve safety by removing left-handed ramps and reducing delays on the side roads with coordinated traffic signals, designed four new bridges, and widened and rehabilitated two existing bridges. We used a special steel temporary barrier to maximize lane widths during construction.
In addition to the interchange, the project included five miles of pavement and guardrail updates along I-35 to improve safety, relieve congestion, and maximize corridor efficiencies. We used the existing roadway’s footprint to add the auxiliary lane—requiring a complex pavement section that shifted the crown to the appropriate location. In addition, we performed a safety analysis along the corridor to determine where clear zone was deficient and where guardrail should be installed.
Funding sources included MoDOT, City of Liberty, City of Pleasant Valley, and an Economic Development Cost Share Agreement by Clay County and Ford.
An interactive presentation to FHWA prior to submittal of the AJR helped smooth their review and approval process.
We released plans of the base design early to allow contractors to propose Alternate Technical Concepts (ATCs) in confidential one-on-one meetings with the ATC review team. This process allows contractors to maximize their efficiency through proposals for construction innovation, construction schedule reduction, and cost savings to obtain the best value for the project that meets or exceeds the base design project goals.
Client Testimonial
GBA staff did an excellent job managing resources throughout the project, including staffing levels and the overall budget. Since the project lasted multiple years, the consultant project manager tracked changes to their overhead audit rate and immediately discussed what changes could be made in order to keep the overall budget on track while meeting the overall schedule and the high quality of deliverables.
– Mark Sommerhauser, MoDOT