The concept of passenger and freight operations co-existing in shared-use corridors is central to the expansion of intercity and commuter passenger rail service in the United States. All current Amtrak service is on shared-use corridors. Most of the future plans developed by states for enhanced rail service are based on the shared-use corridor concept. The Passenger Rail Investment and Improvement Act of 2008 and the American Recovery and Reinvestment Act of 2009 contain federal funding guidelines for high-speed rail projects on shared-use corridors that require states, host railroads, and Amtrak to reach service outcome agreements regarding frequency, trip time, and reliability before federal project funding is provided. This requirement is designed to ensure that adequate infrastructure is in place to support service outcomes when new or expanded passenger service commences. Passenger service providers are interested in on-time performance and minimizing delays. Freight railroads are interested in minimizing delays and maintaining fluidity. Capacity models are often used by host railroads and passenger service operators to identify capacity issues in a given shared-use corridor and to determine the level of track, signal, and structure improvements that are required in order to add additional passenger service in a manner that supports all operations. These models have the potential to simplify the time-consuming negotiations among states or other agencies operating passenger rail systems, Amtrak, and host railroads that are currently necessary to establish the required service outcome agreements. Capacity models are designed to simulate passenger and freight movements in a given corridor within a network. They are complex in their application, data intensive, require the cooperation of the host railroads, and demand significant experience and skill in properly interpreting and applying their results.   While host railroads typically possess the years of experience and knowledge necessary to operate and use their capacity models, state transportation agencies vary in their levels of experience and knowledge. The methodology and ground rules for using these models can vary greatly depending on how the modeling analyses are structured, the needs and preferences of the particular railroad, and the specifics of the rail corridor and proposed project(s) that are intended to increase capacity.   To aid all parties in the negotiation of service outcome agreements, state transportation agency staff and other stakeholders would benefit from understanding the methods that the host railroads use to calibrate and apply capacity models to determine if adequate capacity exists to support new or increased passenger rail service or if infrastructure improvements may be necessary.

 

 

The objective of this research is to produce a guidebook that state transportation agency staff and other stakeholders may use to better understand the modeling processes and results that support the negotiation of service outcome agreements for the shared use of rail lines for freight, intercity, and commuter rail operations.  The guidebook will examine the modeling processes and results that are used to define, measure, simulate, and evaluate railroad capacity. At a minimum, the guidebook will cover (1) the appropriate use of modeling as a component of collaborative decisionmaking on operational strategies, maintenance activities, and infrastructure configurations; (2) how relevant measures of capacity and performance (e.g., speed, delay, throughput, and operational flexibility) differ and are common for different railroad operators; (3) the modeling assumptions requiring agreement among the parties; and (4) real world examples to illustrate the guidebook.

STATUS:  The research is complete and has been published as NCHRP Report 773 Capacity Modeling Guidebook for Shared-Use Passenger and Freight Rail Operations.