We supported critical repairs to the Lincoln Tunnel Helix structure by evaluating detour impacts to ensure minimal disruption to traffic on the NJ-495 Corridor in both New York and New Jersey. Following the successful project, we assisted with future redesign studies and advanced traffic simulations, including connected autonomous bus analysis.
The Lincoln Tunnel is one of the busiest river crossings in the world, connecting the city of Weehawken, New Jersey to Upper Manhattan. To go between the tunnel and New Jersey Route 495, drivers must use an elevated spiral bridge freeway known as “the Helix.” In the late 2000s, the Helix was in desperate need of repair, which threatened to be very disruptive to not only traffic in New Jersey but in Manhattan as well.
The Port Authority of New York and New Jersey (The Authority), which operates and maintains the Helix, asked KLD to help evaluate construction on the outbound lanes of the Helix, which would impact traffic on the Manhattan side of the tunnel. The Authority proposed to route outbound traffic on the inbound roadway of the Helix, and then create a crossover to get it back to the correct side of the road before rejoining the highway network.
The Authority wanted to present to city stakeholders a solid plan for how they will minimize traffic impacts to Manhattan streets while repairs take place. KLD led the modeling and analysis for this exercise.
Our role was simple, which was to apply our traffic engineering expertise to the Authority’s crossover idea. We expanded NYCDOT’s Manhattan Traffic Model (MTM) to the New Jersey side of the tunnel, making sure to capture capacity, merging, weaving, and queuing from the crossover and simulating traffic during nighttime conditions. We then tested it with and without the closure and assessed the effectiveness of each alternative.
The model was used to estimate what the impacts of the detour would be, including the magnitude and duration of queues and delays. Project deliverables included a fully calibrated and validated base model, models of the alternatives, and a final report including comparative Measures of Effectiveness (MOE).
The detour we tested was approved and the repair work was successfully implemented. The Helix fix was completed in 2015. We continued supporting the Authority with their traffic analysis needs and complex simulation modeling as part of the conceptual redesign study of the Helix. We used our experience in the first project to build an expanded model for the Authority to focus on future year analysis.
We also used the model to perform an analysis on connected autonomous buses and how the Authority could use technology to improve the capacity of the bus lane. We created hundreds of scenarios running simulations to evaluate the technology.
