Expanding American Rail Capacity

Updated 2021-04-09 @ 15:32 with new information on San Diego’s timetabling efforts.

Amtrak recently released a map outlining a $25 billion proposal for expanded passenger rail service in the US. With a focus on improving corridor services, this map would increase Amtrak’s focus on the sorts of short and medium-distance markets where well-operated rail services can be most competitive with driving and flying. Though certainly too limited an intervention relative to the overwhelming need for low-carbon, car-free transport in this country, the map does identify a number of important corridors for rail service expansion in the US, providing a useful starting framework for further improvement.

The largest barrier to realizing this vision is the fact that Amtrak does not own most of the routes on which they seek to improve service. Outside the Northeast, the national passenger carrier relies on rights to run its trains over freight trackage. This saves Amtrak the hassle of maintenance, but the resulting freight-passenger mixing (which takes place on the freight railroads’ terms) is a major source of delays. It also presents a limit on network growth: if adding (more) passenger service to a line will have a significant negative impact on freight operations, freight railroads may deny Amtrak operating rights for that additional service. Amtrak seemingly is testing a more aggressive approach towards these operating rights, but it seems a fair assumption that Amtrak will perpetually face some level of frequency and reliability constraint from freight intermingling in the current rail operations paradigm.

This begs the question: how do we go about implementing Amtrak’s map? Though the median rail mile in the US is lightly utilized, commencing service on a number of key corridors (for example the Los Angeles-Phoenix-Tucson line) will require Amtrak to gain access to extraordinarily busy freight arteries. If the passenger carrier is to run trains at any reasonable frequency over these routes — much less expand beyond them — it will either have to pay its own way with new infrastructure, or find some way to ‘expand the pie’ of rail capacity. We currently tend to accept the former approach, but in the latter there lies massive, unrealized potential. Undertaking national rail capacity planning and beginning to shift America’s railroads towards fully scheduled operations could facilitate a massive expansion of medium-speed passenger service without the construction of much new infrastructure.

The Issue, in Greater Detail

The root of the freight-passenger mixing issue lies not in some nefarious desire on the part of the freight railroads to delay passenger trains, or one on the part of Amtrak to inconvenience their hosts. Instead, the problem stems from the fact that Amtrak and freight carriers exist in fundamentally different operating paradigms.

Most obvious is the fact that American freight trains are slow. The fastest of freights on the country’s best maintained lines top out at 70mph, with most train-miles spent cruising below 50. Passenger trains — theoretically — can run much faster. On relatively tangent track, conventional trains can reach speeds well over 100mph. This inevitably causes conflicts: passenger trains will catch up with freights, and without another available track with which to overtake the freight, the passenger train may have to slow down.

Yet this difference in speed is not the core of the issue. Rather, it is scheduling which drives the fundamental inability of railroads to make these interactions work. Passenger trains are generally run on an exact timetable. Trains are scheduled down to the minute, and are expected to meet those schedules with little room for error. Precision is important not just because us humans dislike waiting, but also because reliable passenger operations generally demand an exact operating plan: schedules lay out where trains moving in opposite directions on single track will pass, where others will overtake, and where still others will make cross-platform connections.

American freight railroads operate in a different environment. Most modern railroads run at least some trains with schedules, but these schedules are hardly the same as those used for passengers. Hours-wide error bars around scheduled arrival times are typical; schedules here serve more as a rough guideline for customers and a means of organizing connections between trains, rather than a precise operating plan for each individual train movement.

Mixing these two operating models often leads to delays and capacity loss for both freight and passenger users. I made a graphic to help visualize some of these issues; the upshot is that it is very expensive to build infrastructure that will allow passenger operations to be resilient to highly variable freight movements. This is especially true on busy or capacity-constrained lines, where dispatchers have fewer opportunities to fiddle with freight train movements to clear a path for passengers.


There are essentially three ways of fixing this problem:

  1. Build lots of new infrastructure along freight lines
  2. Separate passenger and freight traffic onto separate lines
  3. Run freight trains on passenger-style schedules

Let’s take a close look at each.

Building New Trackage

Historically, this model has been the one pursued when adding passenger service. The Chicago-Saint Louis corridor provides a useful example. Upgrades to that corridor (whose freight traffic load is not terribly heavy) in the 2010s involved building 24 miles of additional trackage just to accommodate the greater interference that would come with higher speeds — service levels have remained constant since the aughts. Even with this new infrastructure, trouble continues: before the pandemic, the Lincoln Service’s on-time percent hovered in the mid-70s. This mixed approach is the best in freight-owned corridors with light traffic and significant excess capacity (eg. the portion of the Chicago-Des Moines corridor which runs on Iowa Interstate trackage), but where both passenger and freight volumes will be nontrivial, a different strategy is needed. High frequency/high(er) speed passenger service and high variability freight service simply do not mix well; on these busier corridors, we will either end up building massive amounts of new infrastructure to facilitate mixing, and/or suffer delays in perpetuity.

Separating Passenger and Freight

The North American rail network was built up by a multitude of railroads, with little centralized coordination or infrastructure sharing. This mode of development means that we have built significant amounts of duplicative rail infrastructure. Though some such lines have been abandoned over the years, significant amounts of parallel trackage remain — and often continue to be operated by separate railroads with little coordination. These corridors present a unique opportunity: by separating passenger and freight traffic onto parallel lines, we can realize the benefits that come with exclusive passenger ownership without severely impeding climate-friendly rail goods movement.

Take the example of the Buffalo-Cleveland corridor. The two large eastern roads (CSX and Norfolk Southern) own lines between these two cities, serving same intermediate markets, and often running but feet from each other. If we could encourage the two railroads to work together, we could run the handful of daily Norfolk Southern trains which use their line over CSX’s tracks, and gain a (nearly) freight-free passenger corridor between two large cities — one of the pairs identified for improvements on Amtrak’s map.

This is a relatively extreme example of duplication, but hardly the only such case. Across North America, opportunities for this sort of redistribution abound; whether it be Chicago-Milwaukee, Chicago-Porter, Portland-Spokane, Detroit-Toronto or otherwise, myriad corridors present opportunities for planners to realize passenger capacity through increased inter-railroad cooperation. This is not to say that investment needs magically disappear when you put passenger and freight on separate routes — network restructuring will almost always involve investments in capacity and connectivity — but when the dust settles, you are left with a passenger corridor whose future service levels and service consistencies are unconstrained by freight movement, and a freight corridor which can operate without the delays and capacity losses associated with passenger service.

Notably, this is an approach which has been implemented with great success before. Until the late 1970s, Amtrak’s Northeast Corridor was extremely busy with freight traffic, handling dozens of daily freight trains for the Pennsylvania Railroad (and later, Penn Central and Conrail) on top of the Corridor’s heavy passenger traffic. For all the reasons discussed above, this was a rather inconvenient arrangement.

When the federal government took over six bankrupt northeastern railroads in 1976 and created Conrail, they made it a priority to reroute freight off of the corridor. After upgrading roughly parallel assemblage of routes through the region, and restructuring yards and interchanges to feed it, Conrail shifted freight traffic off of the Corridor, and today, most of Amtrak’s route is free of through freight movements.

Another example comes from Ontario. In the 1960s, Canadian National used a combination of existing trackage and new construction to create a circumferential line around Toronto, allowing its trains to access a new yard north of the city and avoid congestion in Downtown Toronto. This freed up significant capacity on the legacy routes radiating out of downtown, which in turn allowed the commencement of commuter rail service and the eventual purchase of many of those corridors by the regional transit agency (Metrolinx) in support of rail service expansion.

That both these examples come from railroads rerouting trains within their network should not be lost on us: in corridors where the duplication comes from parallel routes of different railroads, implementing traffic separation would require gaining buy-in from multiple freight railroads and would necessitate a willingness to share infrastructure. This is certainly not without precedent or existing frameworks, but it does add another level of complexity in negotiations.

For this reason, legislating a greater governmental role in the management of the rail network is likely necessary to realize the full potential of duplication, or any other major intervention in rail capacity planning. Inter-railroad disputes are simply much easier to handle and forecast within a stronger planning framework, a model which separates infrastructure management from rail operations, or simply a nationalized network. As we evaluate those frameworks, simply exploring these opportunities where they exist seems a worthwhile investment of our time and energy; it is likely that paying railroads to play nice with each other in key corridors will still provide a less expensive (and more reliable) path to network growth than our current mixed traffic model.

Scheduling Freight

Another approach to this problem comes through scheduling freight movements. The United States is not alone in running freight trains flexibly — some Eastern European countries, for example, do as well — but in nations where high volumes of freight and passenger traffic must mix, scheduling is the solution. Switzerland provides an instructive example. Swiss rails handle about twenty percent of intercity ground passenger-kilometers, as well as about thirty five percent of freight ton-kilometers. The former figure is (by nearly a factor of two) the highest in Europe; the latter is about equivalent to the US’s freight rail mode share. Swiss railroads manage these interactions by scheduling everything. Instead of running trains on a flexible schedule like in the US, freight movements are rigidly timetabled like passenger trains. This allows precise, high-capacity and high-reliability freight and passenger movements — saving the country the expense of building costly new infrastructure, and increasing the competitiveness of both rail services’ offer.

An example of such an implementation in North America comes to us from San Diego. After I posted the original version of this piece, Brendan Dawe flagged some fascinating materials about service coordination and design on the rail line linking Orange County to San Diego. In response to planning goals of increasing passenger rail frequencies and allowing more freight movement to and from the Port of San Diego, BNSF and the local commuter operator developed short, medium and long term timetable plans for the route, and are building their future investment priorities around those efforts. By tightly scheduling freight movements, the corridor’s users will realize increased capacity with comparatively low levels of new investment. Needless to say, this plan (which was implemented in consultation with Deutsche Bahn), provides a useful domestic proof of concept in strict freight timetabling — one which can serve as a guide for similar efforts.

In analyzing cases like this one, we should not lose sight of potential barriers to timetabling. Fully structured freight operations may cause freight railroads’ operating costs to increase in the short run as their ability to make operating plan adjustments for demand is reduced, and as their trains are forced to follow stricter performance guidelines (exemplified in the second slide above). A shift to timetabled operations would also require the development of new network planning competencies among American railroads; presumably, in the long run, freight carriers would not want to rely on Deutsche Bahn’s planning capacity.

Yet San Diego’s experience also speaks to the broader potential upsides of scheduled operation. With timetabling, passenger movement over freight trackage becomes significantly easier to coordinate and cheaper to implement. Moreover, freight railroads likely would realize a medium and long run commercial benefit from a move to fully structured operations. Other American research has (unsurprisingly) found that timetables increase track capacity, reduce long-term investment needs, and perhaps most importantly, reduce the service variability that so hobbles’ railroads ability to compete for freight in the age of ‘just-in-time’ logistics. Implementing fully scheduled rail operations is unquestionably a significant change in the short run, but is a change which may end up being key to affecting a shift away from road transport in both passenger and freight movement.


America needs a robust intercity mass transit system, and fast. To decarbonize and shift the nation away from its dependence on automobiles, we will need to spend extensively (and economically) on expanded rail and bus service to better knit American communities together. Unlocking passenger rail capacity on our nation’s freight trackage is only one part of a broader set of necessary changes for our surface transportation system, but it is nevertheless essential. These corridors will not provide us with the high speed network we so sorely need, but they will remain a cost-effective means of expanding the reach of medium-speed rail, and the most expedient means of entering urbanized areas. As we develop infrastructure roadmaps for the coming decades, transforming rail capacity planning thus should be an item near the fronts of our minds.