Innovations in Pedestrian Safety and Traffic Management
Project Overview
The Shawnee Drive over I-635 bridge project, located in Shawnee, Kansas, involved redecking and rehabilitating the bridge. The project also included removing a non-functional sidewalk on the south side of the bridge and replacing it with a wider eight-foot sidewalk on the north side. This improvement aimed to enhance pedestrian safety and accessibility.
Bridge Features
Several notable features were incorporated into the design and construction of the bridge. The bridge’s curved geometry presented additional challenges in design and construction, requiring planning and execution to ensure structural integrity and safety. Shear studs were added to improve the bridge’s capacity, enhancing its overall strength and durability.
Challenges and Solutions
One of the significant challenges of this project was completing the bridge redeck while minimizing impacts on the public and nearby commercial areas. A thorough analysis of the existing traffic at the interchange and nearby interchanges was conducted as part of the Transportation Management Plan (TMP). It was determined that keeping the bridge open would necessitate restricting key turning movements due to the proximity of the ramps. Consequently, a decision was made in coordination with the Kansas Department of Transportation (KDOT) to fully close the bridge, detour traffic and accelerate construction.
Advantages of Full Closure:
- Reduced Construction Time: Construction time was reduced to approximately six and a half months compared to over nine months with phased construction. This allowed the project to be completed in one season, avoiding delays due to winter weather.
- Cost Savings: A shorter construction duration and simplified construction process resulted in cost savings.
- Durability: The bridge deck was constructed to be joint-free, enhancing its durability.
- Minimized Impact: Reduced disruptions to business driveways and existing traffic signals.
- Simplified Traffic Handling: Traffic management at the bridge/ramp terminals and along Shawnee Drive adjacent to the interchange was more straightforward.
- Unchanged Detours: No modifications were necessary for traffic detours or temporary signal requirements.
Innovations and Notable Aspects
The TMP revealed that the detour traffic would adversely affect the Merriam Drive interchange to the south. In response, GBA designed temporary traffic signals to effectively manage operations during the closure.
Community Impact
The project positively impacted the community by reopening the bridge to traffic approximately three months earlier than phased construction would have allowed. This timely completion minimized the duration of construction-related disruptions and ensured the work was finished within a single construction season.
Complexity and Handling
The most complex aspect of the project was determining the construction sequencing. The project team effectively addressed this complexity by opting for a full closure and accelerated construction, resulting in a more efficient and less disruptive process.
Conclusion
Despite the challenges posed by the bridge’s curved geometry and the need to reconfigure sidewalks, the project was completed ahead of schedule. The decision to fully close the bridge and accelerate construction minimized public inconvenience, resulted in cost savings and enhanced the bridge’s durability. This project demonstrates the high standards of engineering and collaboration maintained by GBA and KDOT, ultimately benefiting the Shawnee community by providing safer and more efficient transportation infrastructure.