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Our currency for capacity brings creativity to planning for U.S. freight railroad

January 25, 2022 – 9:14 am

Capacity planning for railroads is tricky business. There are numerous dependencies between vehicles, infrastructure, signaling, and operations. Capacity planning projects in southern California and the Pacific Northwest use an innovative planning approach developed by DB E.C.O. Group.

For railroads that run on a timetable, it is possible to start with planning the desired service, then determine what track infrastructure and vehicles are needed, and iterate until you have an attractive solution. For a freight railroad, however, things are a bit more complicated. Freight railroads do not run according to a schedule. In the U.S., where private freight railroad companies have full autonomy in terms of operation and infrastructure, they run a train when it is loaded and ready to go. In other words, the terminals decide when a service runs and not the route. And it is much harder to define what service the railroad should be designed for, as freight demand can be extremely volatile. How can we know with certainty where freight trains will need to be dispatched and received in five or ten years from now?

This challenge was taken up by a team of experienced consultants from the DB E.C.O. Group in the U.S.

Our team took inspiration from Germany’s Deutschlandtakt effort and DB Netz AG’s Click & Ride app when we offered our support in making infrastructure investment decisions to a major U.S. freight railroad that operates a network of more than 32,000 miles (52,000 kilometers).

From Southern California to the Northwest

Our work focuses on two of their busiest corridors. The San Bernardino Corridor is the gateway to intermodal container hubs at the ports of Los Angeles/Long Beach and to the local logistics and warehousing industry. The other corridor is in the Pacific Northwest between Seattle and Tacoma where the company serves intermodal container facilities and ports for the export of agricultural commodities like grain, in fact, enough grain to supply 900 million people with bread for a year.

Both corridors expect strong demand growth for freight and passenger services, and thus, the company wants to invest in effective expansion projects, appropriately phased, to secure its capacity needs over the coming 20 years. Identifying such projects is difficult in a corridor where the day-to-day operation has to deal with a wide range of train characteristics, fluctuating service needs, and improvised dispatching. A traditional planning effort would try to mimic all this complexity, without any attempt to simplify or bring order to it, and then come up with a long, and costly, list of infrastructure projects to build for “full flexibility”. In this case, the estimated cost of urban expansion in southern California and in the environmentally sensitive area between Seattle and Tacoma made such an approach unfeasible.

„Currency for capacity“

Our team collaborated with the company to develop a more promising approach. One that aims to bring order to operations and structure to the complexity, and to gain maximum use from existing infrastructure in conjunction with dedicated investments. Of course, freight operations will continue to be complex, with varying train lengths, weights, speeds, and service requirements, resulting in irregular departure times and wide-ranging running times. However, instead of trying to simulate this complexity, we simplify, and plan train slots across the railroad using a standard train that operates under standard dispatch rules, representing our “currency for capacity”. For the San Bernardino Corridor this is a train with a length of 8500 feet (2590 meters), a maximum allowable speed of 50 mph (80 km/h), and locomotive power equivalent to three horsepower per ton of train weight.

Using this standard slot as our currency, we first saturate the corridor, while generating an understanding of what prevents us from adding even more slots, whether it be the signaling system, the track infrastructure, or interfaces with freight yards. Next, we iterate between the supply of slots and demand of slots, assess capacity gaps, and identify suitable measures, so as to be able to provide the number of slots required. The result is a grid of slots that brings structure to planning, and which allows railroad investments to be clearly linked to capacity benefits.         

Luckily, we had learned our lesson from previous work and already understood that in a North American freight rail context, these slots cannot be seen as components of “prescriptive” timetables. Instead, the slots describe what the railroad is designed for, i.e. what maximum capacity utilization would look like, while actual day-to-day train operation continues to be based on market demands. The slot grid serves as a baseline for evaluating the additional capacity use of train movements that deviate from the baseline.  This allows our approach to be applied in order to make economically effective decisions on how much operational flexibility is worth paying for and from what point it is good to work towards the ideal train type and operations.

A new approach to “full flexibility“

During the project on the San Bernardino Corridor, it became clear that reduced-speed access to an important intermodal yard, Hobart, is causing capacity loss on the mainline tracks for trains running through to the ports of Los Angeles/Long Beach. Furthermore, uncoordinated passenger services result in an outsized footprint of the passenger operation on the overall corridor, and the lack of staging tracks on the approach to the busiest corridor segments force trains to be parked for extended times in unfavorable locations, while they wait for a track at their destination yard or at the ports to become available. In response, our work proposes targeted investments that allow separating freight and passenger traffic, provide extended landing tracks for Hobart yard, designate new staging tracks, and upgrade the corridor’s signaling system.

While in retrospect these recommendations seem straightforward, they were not on the outset of the project. With unscheduled day-to-day operations in mind, U.S. planners typically focus on building additional main line track, effectively overbuilding the corridor to accommodate calls for “full flexibility”. With this project, we were able to change the narrative and establish a new approach.

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DB E.C.O. Group

DB E.C.O. Group
Torgauer Strasse 12-15
10829 Berlin
Germany
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