Posts about San Diego
Continuing our look at transit systems outside the Washington region, San Diego county has a light and commuter rail network that stretches 117 miles across Southern California.
The 53.5-mile San Diego Trolley, and its distinctive red cars are the flagship of San Diego's network. The light rail system carries an average of 124,000 passengers every weekday, the fourth most among American light rail systems. It also connects many of region's major destinations including downtown, at least one of the naval bases, and the US-Mexico border crossing at San Ysidro.
The Trolley has three lines, and the segment of the Blue Line between downtown San Diego and the Mexican border that opened in 1981 makes it the oldest modern light rail in the US. The first segment of the Orange Line did not open until five years later in 1986, and the most recent extension came along in 2005.
While it covers much of urban San Diego county, the Trolley has its limits. You can't ride to the beach, Hillcrest (a dense urban neighborhood), or popular tourist sites like Balboa Park and the zoo. You also can't take it to University City, a major education and employment center north of downtown, though that will change when the 10.9-mile Mid-Coast Corridor extension opens in 2019.
Two commuter rail lines stretch San Diego's network
At the Santa Fe Depot and Old Town stations, the Trolley shares a platform with the county's Coaster commuter rail line.
Amtrak and Coaster platforms are on the left and Trolley platforms on the right at San Diego's Santa Fe Deport.
The 41-mile line hugs the Pacific coast from downtown San Diego to Oceanside, offering some impressive ocean vistas along the way.
The Sprinter runs between Oceanside and inland Escondido along a 22-mile suburban highway corridor. The line has faced criticism for its low ridership and limited frequency. On weekdays it runs every 30 minutes (even less often on weekends and evenings) and averages about 8,000 riders, despite initial targets of 11,000.
Criticizing the Sprinter for not being as successful as light rail, though, is a little unfair because it's not light rail. Many commuter rail lines only provide good service at rush hour, and thus often have relatively low ridership compared to all-day light rail. As a hybrid, Sprinter strikes a balance between the two, providing better all-day service than commuter rail like Virginia's VRE, but not as good as light rail.
The San Diego Association of Governments (SANDAG), the area's metropolitan planning organization, both plans and funds transit in San Diego. Funded by a half-cent county wide sales tax, it decides what gets built where and when, leading to transit investments being spread across the region.
The San Diego Metropolitan Transit System (MTS) in actually operates the Tolley, and the North County Transit District (NCTD) runs both the Coaster and the Sprinter.
San Diego's centralized planning and funding structure is certainly different from ours. The National Capital Region Transportation Planning Board handles our region's long-term transportation plans, but it is up to the individual jurisdictions to actual design, fund, and build those projects. This means varying priorities, and projects whose benefits aren't immediately apparent across the region as a whole.
Unfortunately, a centralized planning organization with the power of the purse is unlikely in the Washington region because there are too many governments in play. But San Diego's system is an example of what such an organization can do.
For more on transit developments in other cities, check out GGW's coverage of San Francisco BART's new Oakland Airport connector and Dallas' DART light rail system.
There is much confusion over what separates streetcars from light rail. That's because there's no single easy way to tell, and many systems are hybrids. To tell the difference, one has to simultaneously look at the tracks, train vehicles, and stations.
San Francisco's Muni Metro runs both in a dedicated subway and on the street in mixed traffic.
Is it a streetcar or light rail system? Photos by Matt Johnson and SFbay on Flickr.
It's hard to tell the difference because streetcars and light rail are really the same technology, but with different operating characteristics that serve different types of trips.
The difference, in a nutshell
Theoretically light rail is a streetcar that, like a subway or el, goes faster in order to serve trips over a longer distance. But what does that mean in practice?
There are several features of tracks, vehicles, and stations that both streetcars and light rail sometimes have, but which are generally more common on light rail. Thus, although there's no single separating test that can tell the two apart with 100% accuracy, it's usually possible to tell the difference by looking at several factors simultaneously.
Image by the author.
Let's look at each of those factors, one by one.
Lanes and tracks
It's a common misconception that streetcars always run in mixed traffic with cars, while light rail has its own dedicated track space. That's often true, and it's such a convenient and easy-to-understand definition that I've been guilty of using it myself. But it's wrong.
There are too many exceptions to that rule to rely on it completely. Sometimes (though rarely) light rail lines run in mixed-traffic, and there are plenty of streetcars with their own right-of-way. Some streetcars even have subways.
Compare Sacramento's mixed-traffic light rail with Philadelphia's streetcar subway, for instance:
Left: Sacramento light rail in mixed traffic. Photo by Flastic on Wikipedia.
Right: Philadelphia streetcar in a subway. Photo by John Smatlak on Flickr.
In fact, practically every mixed-traffic streetcar has at least a short section of dedicated track. That's true in Atlanta, Seattle, Tucson, even DC. Those streetcar lines don't suddenly become "light rail" for one block just because they have a dedicated lane somewhere. It's just not that simple.
Left: K Street transitway. Image from DC Streetcar.
Right: Toronto's Saint Clair transitway. Photo by Sean Marshall on Flickr.
There are too many streetcars with dedicated lanes for that to be a reliable indicator on its own. Too many lines that mix dedicated and non-dedicated sections. Certainly it's an important data point; certainly it's one factor that can help tell the difference. But it's not enough.
An even simpler definition might be to call anything with tracks in the street a streetcar, and anything with tracks elsewhere light rail.
But that's not reliable either, as Portland and New Orleans illustrate:
Left: Portland light rail. Photo by BeyondDC.
Right: New Orleans streetcar. Photo by karmacamilleeon on Flickr.
Salt Lake City muddies the water still further. Its "light rail" mostly runs in the street, while its "streetcar" runs in an old freight train right of way, almost completely off-street.
Left: Salt Lake City light rail. Photo by VXLA on Flickr.
Right: Salt Lake City streetcar. Photo by Paul Kimo McGregor on Flickr.
Vehicles and trains
If tracks on their own aren't enough to tell the difference, what about vehicles?
It's tempting to think of streetcars as "lighter" light rail, which implies smaller vehicles. Sometimes that's true; a single DC streetcar is 66 feet long, compared to a single Norfolk light rail car, which is over 90 feet long.
But not all streetcars are short. Toronto's newest streetcars are 99 feet long.
In fact, many light rail and streetcar lines use the exact same vehicles. For example, Tacoma calls its Link line light rail, and uses the same train model as streetcars in Portland, DC, and Seattle, while Atlanta's streetcar uses the same train model as light rail in San Diego, Norfolk, and Charlotte. And Salt Lake City uses the same train model for both its streetcar and light rail services.
Left: Tacoma light rail. Photo by Marcel Marchon on Flickr.
Right: Portland streetcar. Photo by Matt Johnson on Flickr.
Left: San Diego light rail. Photo by BeyondDC.
Right: Atlanta streetcar. Photo by Matt Johnson on Flickr.
And although streetcars often run as single railcars while light rail often runs with trains made up of multiple railcars, there are exceptions to that too.
San Francisco's Muni Metro and Boston's Green Line definitely blur the line between streetcar & light rail, perhaps more than any other systems in North America. Some might hesitate to call them streetcars. But they both run trains in mixed-traffic with cars, and some of those trains have multiple railcars.
Meanwhile, many light rail systems frequently run single-car trains, especially during off-peak hours.
Left: Norfolk light rail with a single car. Photo by BeyondDC.
Right: San Francisco streetcar with two cars. Photo by Stephen Rees on Flickr.
Stations offer some help, but no guarantee
Light rail typically has bigger stations, while streetcars typically have smaller ones. A big station can sometimes be a good clue that you're likely dealing with light rail.
For example, look at Charlotte and Portland:
But that's only a general guideline, not a hard rule. Just like tracks and vehicles, there are many exceptions. Light rail often has small stops, and streetcar stations can sometimes get pretty big (especially when they're in a subway).
This light rail stop in Norfolk is smaller than this streetcar stop in Philadelphia, for example:
Stop spacing and route length
Probably the most reliable way to tell streetcars apart from light rail is to look at where the stations are located. Light rail lines typically have stops further apart from each other, on lines covering a longer distance.
This chart explains the difference:
This is the definition transit expert Jarrett Walker favors, and if you have to pick just one or two factors to consider, stop spacing and route length are the best.
But even this is no sure way to categorize all lines as either streetcars or light rail. It might be easy to tell the difference between something with stops one block apart (theoretically streetcar) versus stops two miles apart (theoretically light rail), but what if the stops are 1/4 mile apart? Or what if the gaps aren't consistent? There's no clear place to draw the line.
Furthermore, Walker's graphic itself illustrates exceptions to the rule. The top line shows a light rail route with stops close together downtown, the third line shows a streetcar with some sections that have far-apart stations, and the fourth line shows a very long streetcar.
There are certainly plenty of real-life examples of those exceptions. Before Arlington, VA cancelled its Columbia Pike streetcar, DC and Arlington were considering linking their streetcars with a bridge over the Potomac River. Had that happened, there might have been a mile-and-a-half between stops.
Certainly station spacing and route length provide a convenient general rule, but only that. There's no hard boundary where everything to one side is streetcar, and everything to the other is light rail.
To really know the difference, look at everything
There are seven factors that light rail usually has, but that streetcars only sometimes share: Dedicated lanes, off-street tracks, bigger vehicles, multi-car trains, longer routes, bigger stations, and long distances between stations.
No single one of them provides a foolproof litmus test, because sometimes streetcars have each of them, and sometimes light rail doesn't. But if you look at all seven together and determine which direction the majority of a line's characteristics point, over the majority of its route, then you can usually sort most lines into one category or the other.
For example, DC's H Street line fits neatly into the streetcar category, because it runs in the street almost totally in mixed traffic, with small vehicles on single-car trains, along a short route that has frequent, small stations. Even if DDOT builds the K Street transitway and a dedicated-lane streetcar on Georgia Avenue, the majority of the seven factors will still point to streetcar.
On the other end of the spectrum, Seattle's Central route is squarely light rail. It has a dedicated right-of-way that's often off-street, uses large 95 foot-long vehicles that are usually coupled into multi-car trains, along a long route with infrequent stations.
But even then not every system is crystal clear. San Francisco's Muni Metro, Philadelphia and Boston's Green Lines, and Pittsburgh's T, for example, all have some segments that look like classic streetcars, but also some segments that look like classic light rail. These networks defy any characterization, except as hybrids.
It's a feature, not a bug
The fact that it's hard to tell the difference is precisely why so many cities are building light rail / streetcar lines. The technology is flexible to whatever service characteristics a city might need.
You can use it to build a regional subway like Seattle, or you can use it for a short neighborhood circulator like DC's H Street, or anything in-between. And perhaps even more importantly, you can use it to mix and match multiple characteristics on the same line, without forcing riders to transfer.
That's why many of the most successful light rail / streetcar systems are the hardest ones to categorize as either / or. They match the infrastructure investment to the needs of the corridor, on a case-by-case basis, and thus have some sections that look like light rail, and others that look like streetcar.
That's not muddied. That's smart. That's matching the investment to the need, which is after all more important than a line's name.
Cross-posted at BeyondDC.
In the DC region we have Metro and commuter rail trains, with light rail, streetcars, and BRT all in the works. And of course, regular buses. But one common mode we don't have is DMU trains, which bridge the gap between light rail and commuter rail.
DMU stands for Diesel Multiple Unit. DMU trains are intended to operate on routes that look like commuter rail, but at almost light rail frequency. They go over long distances, with infrequent stations, usually on or adjacent to freight tracks. But instead of coming only at rush hour, trains come all day long, as often as every 15-20 minutes.
That's a great service model for suburban corridors that need something better than rush-hour MARC or VRE service, but are too far away for light rail and don't have the density to justify the costs of Metrorail.
One big advantage of DMUs over traditional commuter trains is that DMUs can operate on-street, like light rail. That makes integrating them with downtown areas much easier, because it frees DMUs to go anywhere, rather than only to a city's main rail hub.
All MARC and VRE trains to DC must go to Union Station, because all the long distance tracks through DC go to Union Station. Not only does that constrain route planning, it's also a limit on capacity, because there are only so many platforms at Union Station. But a DMU could go anywhere.
There are not currently any plans for DMU lines in the DC region, but there could be. DMU would be a great solution for Maryland's proposed Charles County corridor or Fairfax's Route 28. Officials are looking at light rail for those corridors, but they're far out in the suburbs and wouldn't have very frequent stops, so DMU might be more appropriate.
In the long term it might also make sense to convert some of MARC and VRE's existing lines to DMU, or to supplement them with more DMU trains. That would give them more operational flexibility, and could increase service. But MARC and VRE are established as traditional commuter rail, and may be uncomfortable with anything else.
MARC and VRE also have to use tracks owned by freight companies. DMUs can be used in mixed company with freight, although that requires federal approval. But if the freight lines are already using their tracks to capacity, which is common in the DC area, then there's no room for more trains no matter what they look like.
DMU isn't Metro, and it isn't light rail. DMU trains can't do all the things those modes can do. It's not an appropriate mode where frequent stops are necessary. But for long corridors with infrequent stops and moderate capacity needs, it's ideal. We should keep in mind as we continue to advocate for new transit lines.
Cross-posted at BeyondDC.
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