Mixed-Use Rail
Adding commuter rail to freight rail lines not as simple as it looks.
Stand on a bridge in the Chicago suburbs of Highlands or Hinsdale that spans the three-track BNSF main line headed west out of Chicago to Aurora, Ill., during the evening rush hour, and you may see half a dozen or more sets of headlights approaching.
What you are witnessing is the nightly parade of outbound Metra commuter trains on this mostly straight, and therefore fast, stretch of track, nicknamed the racetrack. On an outside track, locals are making every station stop, while on the center track express trains bypass some of the stations. The third track sees a less intense pace of Metra trains headed in the opposite direction, including some that have reached their end-point and are now headed back inbound.
But, though this is very much a commuter train show, often you will find a freight train (and even an Amtrak long-distance train) added to the mix. This is, after all, one of the most important freight routes in and out of the U.S. freight railroading capital, Chicago.
Yes, BNSF, which inherited the line from predecessor Burlington Northern, does try to schedule its freights around the morning and evening commuter rush hours. But, in freight railroading, everything isn’t always predictable, and a “hot” intermodal train has to get to its destination on time, too.
Coexistence
The BNSF racetrack, which has had commuter traffic essentially going back to its beginnings, is one of the best examples of how intense commuter rail traffic can coexist with freight traffic. And it’s a good example because it has almost all of the physical characteristics of the line in its favor.
Looking at the well-choreographed ballet that interweaves trains on this line, you would think that adding commuter rail to an existing freight line should be simple. But you would probably be wrong.
Any Amtrak manager at any level will tell you, it’s almost impossible to maintain a tightly scheduled passenger operation on a single-track freight railroad main line with widely spaced sidings. There are just too many things that can go wrong — and too few options available to the dispatchers who manage traffic on the line. And, on many Amtrak routes, you’re only talking about one or two passenger trains a day in each direction. To offer commuter service on a rail corridor, you need a number of closely spaced trains during both the morning and evening rush hours — and, if possible, additional service throughout the day.
BNSF’s dispatchers on the racetrack have three tracks to work with, accompanied by frequent cross-overs that allow trains to move from one track to another at fairly fast speeds.
Looking to Europe
Rail transit and passenger train advocates often cite European rail systems as an example of how freight trains and passenger trains can coexist — and how railroads can offer fast and efficient transportation services.
One reason European railroads manage to mix passenger (both long-distance and commuter) traffic with freight trains so well is that almost all major main lines are double track, with routes that have substantial commuter traffic often being four main tracks. The latter is extremely rare in North America. Additionally, European freight trains are usually much shorter than those found in the United States, while often having locomotives with the equivalent horsepower assigned to much longer and heavier American trains. That factor lets the European freights move faster — including having quicker acceleration when they do have to stop — and therefore fit in better with faster-moving passenger trains.
And, electric locomotives pull most of Europe’s rail traffic — passenger and freight — on electrified routes. (Switzerland, with abundant hydroelectric power, is the world leader in railroad electrification, with more than 90 percent of its railroad route miles electrified.) Electric locomotives (and electric self-propelled railcars) have a substantial acceleration advantage over diesel power.
