What is the Route Matrix?
Well, its like this: | |
You wanted it in red, maybe? Never fear ... there is a train route map down there under the fold.
The route matrix comes from the difference between airplanes and trains, and is something that many of us have to learn if we want to get ready Sustainable Energy Independent interurban travel:
- Planes comes in distinct sizes. There is a dramatic difference between how they travel and how they pick up passengers. And stopping to pick up passengers is a dramatic interuption of their service.
- Trains have flexible sizes, and can grow or shrink to respond to demands for trips. One train can be picking up passengers while a second train a few feet away is travelling through at speed. And adding a stop will frequently cost five minutes or less on the timetable.
Energy efficiency will push us to favor rail over air. However, if we treat fast trains like slow aircraft running along the ground, we will be doing nobody any favors.
When I have actually explained the title, I am going to declare this diary finished.
Trips Versus Routes
You may have heard me stress a focus on 1 hour to 3 hour trips as the segment where interurban rail can dominate air travel. Just the process of check in and luggage balancing means that air travel has a higher "flagfall" time cost. Add in the fact that trains can serve multiple stations in a metropolitan area in much less time than an airplane can serve a single airport, so that for most people the closest interurban train station will be closer than the closest commercial airport.
The international experience is that a two hour trip by train, if it is price-competitive with air travel (this is a very readable introduction), can gain 60-70% of the market that would otherwise be served by air, and a three hour trip can gain 40-50% of the market.
But this does not mean one to three hour shuttles bouncing back and forth between two destinations! Demand for rail travel does not hit a brick wall at 3 hours ... it simply continues to slide down in market share.
So consider three potential "shuttle" routes, each two hours travel by train, on trains that are fast enough that they are competing against regional air carriers.

Of course, some people may be interested in travelling from A to C by rail, or from B to D, or even from A to D ... but each transfer costs patronage. With an airline, we address this either by adding an additional non-stop service, or by designating one location a hub, and having a large number of one-transfer trips provided via the hub. And, given operating speeds, and the heavy cost of an additional stop, that makes all the sense in the world.
But with an ability to add carriages, and with much less time lost per stop, the sensible thing to do with trains is to make a single, longer, route, that provides a variety of trip services:

How much difference does this make? Well, since we are out here in the dry arid hypothetical space of A-town, B-burg, C-ton, and D-ville, I'll use the following dry, arid, hypthetical assumptions:
- The total air/rail travel market is proportional to the geometric mean of the populations;
- Rail gets 70% of the market for 2 hour trips, 20% of the market for 4 hour trips, and 10% of the market for 6 hours trips by rail
- A-town and D-ville both have 3m people, and B-burg and C-ton both have 1m people
So the shuttle system, with no effort to coordinate between services, is focused on a rail market of about 3.08m:
- 70% of 1.7m (A/B)
- 70% of 1m (B/C)
- 70% of 1.7m (C/D)
However, the extended run has the same 3.08m in the markets it dominates, plus 0.98m in its secondary markets, for a total market of 4.06m:
- +20% of 1.7m (A/C)
- +20% of 1.7m (B/D)
- +10% of 3m (A/D)
That is an extra 30% of the total "shuttle" market. And if it turns out that there is another town, E-lotte, one hour to the right of D, extending the route to include D/E can split the C/E market with air and also grab some marginal shares of the B/E and A/E markets.
"LD" and "MD" routes
This is, after all, why the continent-spanning Amtrak routes through what seem to be the middle of nowhere are closer to profitability than the routes in the Northeast Corridor, in what is supposed to the part of the country where "trains are viable". Those very long routes are what people mean when they talk about Long Distance, or "LD" routes.
But the same logic applies for shorter routes or, if you will, "medium distance" routes. If you have a train that lays over in the middle of the night and starts at 6am, it can be providing:
- pre-working day arrivals in the first 3 hours of its route
- morning arrivals in the next 3 hours of its route
- afternoon arrivals and departures in the next five hours of its route
- after working day departures in the next three hours of its route
- evening departures in the final three hours of its route
... for a 17 hour service day from 6am to 11pm, without once stopping to turn-around.
And the not stopping to turn around is part of the point. While there will not be very many people on that train from beginning to end, a substantial fraction of the patronage will be provided by the overlapping sequence of three to six hour trips.
I promised in the intro that there would be a train route map, and here it is: this is the map of the official Federal High Speed rail corridors (most of these are Express High Speed 110mph, rather than Very High Speed 220mph):

And right away you can see that these may be the express lanes for Express High Speed rail ... but we definitely do not want the Express High Speed rail restricted to these corridors. Consider Chicago / Cleveland via Toledo:
- if that route can continue to Buffalo at 80mph, it can become Chicago (and points west) to Boston (and points north), via Toledo, Buffalo, Albany and Springfield
- if that route can continue to Pittsburg at 80mph, it can become Chicago (and points west) to New York (and points north), via Toledo, Cleveland, Pittsburgh and Philadelphia
So here you see part of the importance of the "level" of rail project that I described (with a term borrowed from another rail context in another country) "Clearway" projects. Chicago/Cleveland is under 4 hours by Express High Speed train ... that is far more effective as part of a longer route than it would be as a shuttle.
And the important there is twofold. First, keeping the route going increases the number of specific trips offered by the route. Second, a longer route requires an opportunity to catch up if it falls behind for any reason. And so it is especially critical that the corridors that interconnect the high speed rail corridors offer the capacity to provide an unscheduled priority path.
And now ... the Route Matrix
All of this, however, is prelude ... none of the above of the route matrix itself. Rather, all of the above is why there are long routes strung out across the country. If we cut back on subsidies, and we allocated the remaining money based on passenger miles per dollar, it is not the "LD" routes that we would be cutting back.
But the route matrix is not looking back ... it is looking ahead. The route matrix is how you interconnect different routes to further multiply the variety of trips on offer.
Here is the late Dr. Adrian Herzog in 1985 discussing (9:20) using the Route Matrix to get an ordinary Amtrak route up to breakeven :
And this is Andrew Selden (9:20) initially discussing (0:00-6:00) how long distance routes radiating from Chicago are performing better than the shorter distance routes radiating out from Chicago, and then discussing (7:20-9:20) the use of the route matrix to build the patronage on the two New York routes to Canada ... the Adirondack to Montreal and the Maple Leaf to Toronto ... by switching the origin of one of the two routes to Boston, and having the two routes interconnect between Albany and Schenectady. He claims that it would double the amount of passenger miles served ... for a very limited increase in cost.
And that is the route matrix ... taking routes that are long enough to be effective, and then integrating their schedules to multiply the variety of trips on offer.
What do you need to do for a more tightly integrated system? Well, the same thing that you need to get more patronage on existing routes, but even more so: greater reliability. Take two services on independent corridors that each run on time 95% of the time, and the pair will be running on time more than 90% of the time. Take two services on independent corridors that each run on time 75% of the time, and the pair will be running on time less than 57% of the time.
This is also why it is so easy to underestimate the benefit of Clearway type projects. The benefit of the first Clearway project in a corridor is likely to be modest. However, after eliminating the most serious bottleneck in a corridor, that bottleneck is out of the way of all other potential projects, so the benefit available from all other potential projects in the corridor has increased.
In other words, there are Network Economies offered by each Clearway project, in addition to the direct benefit that it provides. And if the total network benefit supports sufficient reliability, then the train network can take the step up from a series of individual routes to an interconnected, integrated transport system.
And something that would get much of the current Amtrak-type train services off subsidy ... when added to the benefit of Express High Speed rail, the opportunities are even more dramatic.
And that is the Route Matrix Revolution.
All Done!