A highly competitive industry, intermodal transportation requires ports to provide adequate infrastructure to support growing freight volumes while satisfying higher service expectations. In addition, ports must expand their infrastructures without negatively impacting the environment or public health and safety. In Southern California, for example, the increase in imported goods from Asia has pressured the Port of Los Angeles and Port of Long Beach to design a sufficient dock-to-rail system that would keep freight containers that would normally be moved by truck away from freeways and adjacent housing communities while supporting future increases in volume.

On the opposite coast, transportation-planning challenges are equally prevalent. During recent years, the New York Economic Development Corporation (NYEDC) has been exploring the economic feasibility of providing a cross-harbor freight tunnel to connect New Jersey with New York. While there would be numerous advantages to building this freight system in an extremely impacted area, NYEDC needed to determine and justify the level of investment required and the environmental impact that would result from the supporting infrastructure.

STV Group, Inc., a leader in transportation engineering, engaged AAI to contribute insight and simulation analysis for an environmental impact study. The goal was to analyze various infrastructure alternatives and determine the level of supporting infrastructure needed outside of the tunnel on the New York side of the network. STV used AAI's Transportation Model Studio (TMS) to support major decisions and public outreach associated with the study.

The planning and engineering team involved in the environmental impact study had various infrastructure alternatives to evaluate. TMS was used to represent three infrastructure scenarios that varied from low to high environmental impact:

• High: two tracks in the entire network east of the tunnel
• Medium: a portion of the network that only contained one track with the remaining containing two tracks
• Low: same number of tracks as the medium scenario, with even more of the network containing one track

The ability to analyze various infrastructure levels for this project was paramount. The team's goal was to determine the design that would efficiently support intermodal activity, reduce costs and minimize environmental impact.

The same projected operational plan was used to evaluate the performance capabilities of each of the scenarios. The operational plan consisted of a schedule of all tunnel-based train traffic as well as "through" traffic on the New York side. For each scenario, the cumulative amount of delay experienced by the trip volume was tracked and reported by the TMS model. This amount of delay was used as a primary measure of effectiveness when comparing alternative networks.