Why is there no Express Light Rail?

Why doesn’t anyone, anywhere in the US run express light rail?

No, seriously.

There’s nothing inherent about US LRT technology which says every train has to run the same boring route all the time. Sidings and pullouts and overtake points are entirely possible. Actually, US LRT has about the same approximate loading gauge as the Japanese 1067mm network. And those guys are the masters of this shizzle. Check it:

That’s a Keihan 7000-series overtaking what looks like a refurb 2400 series on the far side of the platform. Local shows up, express shows up a minute later, express takes off, local follows. I’ve actually seen a video of a four-train meet at this stop – NB and SB locals arrive within 30 seconds of each other, NB and SB expresses show up simultaneously, expresses depart, locals follow.

I don’t expect North American operators to have the ability to run the tight, exact headways of a suburban Japanese railway, but the basic principle is quite possible. The local just has to chill for maybe 5 minutes instead of 2.

Where would this work? Well, lots of places, but for a system that particularly cries out for express LRT, look no further than this proposal for Raleigh-Durham-Chapel Hill. Yonah has a very nice diagrammatic map up detailing their proposed LRT and commuter rail lines.


The Raleigh-Cary side is 18 miles, and a full 10 miles of those directly parallel the commuter rail, from West Morgan to Cary Parkway. Likewise, the Durham-Chapel Hill side is 17 miles, and 4 of those are parallel to the commuter rail. The distance between endpoints for the LRT is 15 miles.

So: 14 miles of redundant commuter rail to connect to a 15-mile “core” section.

But why not just build a single-track LRT track in between cities? Run LRVs on commuter rail frequencies in between the cities, run them on typical LRT frequencies within. Same service plan, but a single technology. They could save themselves from building a bunch of redundant systems. Not only that, but most transit agencies own their own LRT, fee simple, where the freight railroads keep the tracks. Transit agencies paying to improve freight railroads for commuter trains essentially amounts to giving some dude money to buy himself a house, in exchange for him agreeing to let you sleep there.


Suppose Raleigh and Durham were connected by continuous LRT. There might be a case for the Greenfield-Parkway-to-Downtown-Raleigh segment as a standalone DMU line. You know, grab some RDC’s from somewhere, or something. But there’s no way the single station in “West Durham” would justify its own commuter rail spur if LRT was continuous. There is, then, eight miles of proposed commuter rail on the Durham side which is duplicative, which brings us to 18 miles of redundant commuter rail to bridge a 14-mile gap.


So what should this thing look like instead?

The stupid, idiotic, dumb move would be to say, “well let’s just build one rail system, durrr,” construct LRT between the cities using the same doubletrack cross section as within them, and add in a bunch of extra stations in the RTP area because hey, that powerpoint handout you got says that “light rail” stops every 1/2 mile to a mile, as opposed to “commuter rail” which stops every 3-5 miles. Congratulations, you have now created a slow loris rail that takes two hours to go from end to end.

No, the planners have got it figured right that the demand within Durham and Raleigh is different than the demand between the cities, it’s got different req’d peak frequencies, different baseline service levels. But there’s no reason not to operate it over a single track network using a single contiguous technology. Like this:

Midday operations might work like so. Trains originate at Northeast Center every 15 minutes. Every other train becomes an express from Downtown Raleigh to Cary Parkway, stopping only at NCSU and Downtown Cary. Meanwhile a “shorty” local train originates in Raleigh one minute after the express leaves and runs the rest of the way to Downtown Cary. This keeps 15-minute service at all local stops while allowing a single-seat ride from Raleigh and points Northeast to Durham-Chapel Hill.

All the locals turn back at Cary Parkway, but the expresses continue on, through RTP, all the way to Durham/Alston where they revert to locals and run to UNC. Locals originate at Alston on a staggered 30-minute frequency so that there’s 15-minute coverage over the Durham-Chapel Hill line.

This gives you 15-minute service over the LRT segments and 30-minute service over the “commuter rail” segments, but Northeast Center to UNC is now a single-seat ride of about 75-80 minutes in length. Not at all bad, for a trip that’s 35 miles even via the most direct auto route.


Once you define UNC-Durham-Raleigh as a single continuous line, you realize that it’s crazy indirect for endpoint to endpoint trips – most notably the large swing to the north from Chapel Hill to Durham and back. For a starter line, that’s great… but with a single-technology system, you can add shortcuts and expansions later.

Yep, that’s bee-line UNC-NCSU service plus a direct airport connection. It’s really not any different than a big train set. Buy the basic kit with oval of track and sleek locomotive! Then add variations for an even more fun setup!

But you can’t do this if you’re starting out with some balkanized, Philadelphia-type system where everything is a different and incompatible mode. Nope. You need Express Light Rail. But… no one’s done it. Anywhere, in the entire US – at least in modern times.


9 thoughts on “Why is there no Express Light Rail?”

  1. I could criticize the idea of running a half-hourly service that only saves four minutes, but whatevs. This is an idea that’s gotta happen. SJ gets props for doing it first, however tentatively.

  2. The issue is light rail is limited to speeds of 40-45 mph, if you want speed you will need heavy rail which can reach speeds of 65mph.

    What is the point of express service if it is not any faster.

  3. Absolutely not true. The only vehicles with a top speed that low are the Skoda/Inekon/United Streetcar, which are sold as “streetcars.”

    EVERY modern LRV sold in the US can do 55, typically governed to 58.

    The Kintetsu LRVs used by Dallas can do 65, The Siemens P2000’s on the LA Green Line can do 65, and most every Avanto made can do 65, including those used in Houston.

    Moreover, LRVs have superior acceleration to diesel commuter rail (the magic of electric traction is that maximum-torque-at-zero-RPM thing), and would provide superior travel times in many contexts. They’d need more comfortable seats, though…

  4. This is an interesting thought. As you mention, in order to make this work, fast and comfortable LRVs are key. Is there anything out there that can hit 70 but still accellerate and brake fast enough for running in dedicated on-street tracks where necessary?

    The one downside of these sorts of designs where overtakes happen at stations is that they require the most land precisely where it’s most precious: at the stations that are significant enough for both express and local trains to stop. You’re left with six tracks in the corridor right through the center of downtown Raleigh, downtown Durham, NC State, and downtown Cary, and these are basically the only places in the corridor where there isn’t more than enough land to do whatever you want with. Now, I’m not saying it’s intractable and a design that works can probably be found, plus land values aren’t all that high in the Triangle, but on the other hand, assuming the transit referendum passes, we also don’t have that much money to work with in the first place either.

    Another thought: When you’re already doing the grading and building the substations and headspans and whatever for a single track light rail line, how much more does it cost to add a second track the whole way? Almost certainly it’s much less than a 100% cost escalation but I’m not sure how much less.

    I have a suspicion that the commuter rail line is being planned as an excuse to double track the NCRR

  5. (Completing the previous thought)

    … as an excuse to double track the NCRR which will conveniently dovetail with NC’s intercity and high speed rail ambitions in the future. An interesting point to make here is that in NC the corridor is state-owned, so while improvements made on the NCRR corridor do provide some benefit to freight railroads, I’m pretty sure the improvements will be owned by the state.

  6. Baltimore built a largely single-track LRT line, and when ridership got to the point where double-tracking was required, they shut it down to reconstruct. Took a frickin’ decade for ridership to recover.

    So I’m a huge fan of just double tracking from the get-go.

    I drew the UNC-RTP cutoff singletrack on that map because presumably, having the cutoff out of service for a future doubletracking wouldn’t cause the same massive ridership wastage as closing down an entire line and forcing all riders into bustitution. But if there was a ton of federal funding for transit available then yeah, by all means.

    As far as combining high top speeds with high acceleration, the North Shore ran the Electroliners in Milwaukee street traffic (even stopping at stop signs!), then took them up to 90 on the private ROW. I also listed a bunch that can do 65.

    I have a theory that the lack of higher top speeds in LRT has as much to do with the types of people drawn to the public transit planning bureaucracy as it does with any technological limitations. To a bunch of people in Washington DC, 65mph is fast. Whereas I think if you tried to get a bunch of TxDOT guys from the Beaumont District to spec out an interurban light rail vehicle from scratch, like SEPTA does with their commuter rail, they’d probably insist on a top speed of 80 or 85.

  7. And in response to your second message, yeah, if the commuter rail cash is sort of a first offensive in a push towards incrementalist HSR, then it’s probably a pretty okay place to throw some federal reserve notes. But I still think that a single conjoined system with express and local service is preferable to a bunch of different modes and transfers.

    Tokyo’s promiscuity, where you have rural express trains running in the subway, urban subways running out onto commuter lines, high-platform trams, dogs and cats living together, that’s sort of the ideal I think.

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