High SMART frequency on the cheap

In response to my analysis of SMART’s potential for double-tracking, commenters Richard Mlynarik and the Drunk Engineer pointed out that other rail lines run high frequency with sidings only and not a full-fledged double track.  SMART, they reasoned, would save a bucketload of cash by building something similar, and they’re right.

At 15 minute headways, SMART will have at most 6 trains going in each direction once it reaches full build-out.  If they stick to precise scheduling, they will pass at 6 predetermined points. Under the current plan, SMART will run 30 minute headways under a similar scheme, with only 3 passing points of 4 miles each. At that 4-mile standard, we would need another 12 miles of track (another 3 sidings) to permit 15 minute frequency.  While my original assumption was for 56.7 miles of construction (70.5 miles minus the 1.8 mile Puerto Suello segment minus 12 miles of passing track), with this dramatically reduced need for new tracks we can shrink the cost by a similar margin. Rather than cost $284 million, 12 miles of track will only cost $60 million. That’s much more reasonable.

California regulations treat sidings differently than regular two-track systems, and pegs the minimum width of the right-of-way at 50 feet, rather than 44.  While that means the sidings will interfere with the mixed-use path in the narrower segments of the right-of-way, moving the path is far cheaper than extraneous track.

Though this doesn’t give SMART operational flexibility to raise and lower frequencies or speeds at will, the currently planned system doesn’t either. Any changes in frequency or speed will require some capital investment to ensure passing tracks are where they need to be. Compared to the cost of SMART’s trains, though, it’s not much of an expense.

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Can SMART Double-Track?

Photo by Dave S.

The currently planned SMART line, while a much-needed addition to our region’s transportation mix, is inadequate as a car replacement.  The trains will run every 30 minutes during rush hour, once in the middle of the day, and not at all at night.  This is well below the generally accepted 15-minute minimum for show-up-and-go service that you would get on BART.  To bring SMART up to that level of service will require an investment, but not as dire an investment as typically thought.

The easiest problem to solve is that of mid-day service.  SMART should just run trains during that timeframe, problem solved.  Freight could roll during the unused nighttime hours.

The problem of long headways, however, is a physical constraint.  SMART operates on a single-track corridor with sidings to allow trains to pass one another as they move in opposite directions.  The double-track segments will make up about 17% of the corridor, but that’s just enough to allow 30 minute service and not much more.

To double-track, California law requires a 44-foot right-of-way: 15 feet from the track’s center (centerline) to the edge of the right of way, 14 feet from centerline to centerline, and 15 feet on the other side.  SMART’s corridor typically includes a mixed-use path as well, which is another 12 feet wide, bringing the preferred right-of-way width to 56 feet.

The Puerto Suello Hill tunnel in San Rafael. It doesn’t look terribly wide, but SMART pegs it at 30 feet. Photo by D kosdrosky

While most of the right-of-way is wide enough for two tracks and the path, in three locations – Petaluma, Novato, and San Rafael – the width available drops to 50 feet and the mixed-use path will need to be moved to a parallel street.  Still, in each of these segments it’s trivial to double-track. In San Rafael, however, we face a much different situation.  The right-of-way narrows to 30 feet from Puerto Suello Hill to the Downtown San Rafael station, substantially less than required by California for a second track.

Thankfully, the segment is short enough that it doesn’t need the second track.  The 1.8 miles will take about 2.5 minutes to traverse.  If we include a 2 minute pad and schedule our northbound and southbound trains to arrive at San Rafael at the same time, there will never be any conflict and therefore no need for a second track.

This solution does introduce some constraints on future SMART operations.  Dwell times would need to be introduced to ensure punctuality at San Rafael.  Headways could never be less than 7 minutes at current speeds (2.5 minutes for the southbound train to clear + 2.5 minutes for the southbound train to clear + 2 minute pad).  It might be possible to double-track the tunnel, which doesn’t need as much width, and squeeze out another minute of headway, but by then there would be other problems of capacity that could be solved more cheaply.

The cost-per-mile of double tracks varies from project to project.  A double-track project in Carlsbad had a cost of $9.68 million per mile; another project in New York State had a cost of $5.28 million per mile (PDF); and a third in Florida gave about $5 million.  These give an estimated cost of between $284 million and $549 million.  The lower figure is more in line with industry standards, and it’s roughly half the cost SMART will spend on physical rail on its existing right-of-way.

The last piece to the puzzle, rolling stock, is similarly expensive.  The Nippon-Sharyo DMUs used by SMART cost $6.67 million per train.  At my proposed 15 minute headways, SMART would need 15 trains, 9 more than currently on order, at a cost of $60.03 million.  At the maximum service of 7 minute headways, SMART would need 28 more trains than currently on order, costing $186.76 million.  The next logical steps – electrification to speed trains, grade separation to eliminate street crossings, and automated trains to decrease costs – would squeeze more capacity out of the line, but that’s beyond this exercise.

We do this for transit and frequency

Every city on the route, except Novato, wants to accommodate new construction around their SMART stations.  Given the trendiness of smart growth and transit-oriented development, city planners and councils are giddy with the possibilities.  In Windsor, the city has applications for 1,150 new apartments despite the fact that Windsor isn’t even on SMART’s initial operating segment.

Yet there won’t be much rail transit for them to orient around.  Buses can take up the slack, but they are slower than SMART and are forced to mix with traffic on 101.  The train will outperform buses in every measure except frequency of service, and providing more of that premium transit product would keep more people off the roads.  One ridership study for a SMART corridor with 15 minute headways estimated 24,000 trips per day, a sizable percentage (one-quarter to one-third) of the transportation market between Sonoma and Marin.

But this project is for a Phase 3, not for the current IOS.  SMART has yet to prove its worth to the North Bay, and the North Bay has yet to prove it can support a rail line.  The density of jobs, residences, and activities is currently quite low near the planned stations.  The capital improvements needed are expensive, as are high frequencies, and it’s not clear they would be worth the investment.  SMART can’t write off that possibility, however, and needs to engineer its tracks to allow double-tracking in the future. Though it styles itself a commuter rail, SMART could be the primary transit artery for Sonoma and Marin, and it needs to be ready to fill that role if it comes. Until then, the least it could do is run trains whenever it can: 30 minute headways, all day, every day.

Mid-Week Links: Formalization

Marin City Sunset

Marin City at sunset. Photo by Veit Irtenkauf on Flickr.

Marin County

  • Marin City is pondering incorporation. Though it would give the community of 6,000 greater independence in some respects, it would also mean higher costs, its own RHNA, and added responsibilities now taken care of by the county. (IJ)
  • Skywalker Properties was partially to blame for the Grady Ranch debacle, at least according to the state water board, because it knew certain aspects of its creek restoration effort were “unacceptable.” (IJ)
  • New housing guidelines are in development for unincorporated Marin, and the county wants your input. (Pacific Sun)
  • And…: The Marin District Attorney has launched an investigation into a $350,000 housing loan given to former RVSD general manager Brett Richards. (IJ) … Belvedere has an interim city manager. (IJ) … Fairfax to get electric vehicle charging stations. (IJ)

The Greater Marin

  • Metro Atlanta rejected a major investment in its transportation infrastructure on Tuesday, turning down a 1% sales tax in all but three of its regions, which will see their own investments. Transit advocates are, of course, disheartened. (Streetsblog)
  • The fiscal health of a city is related to its urban form. Sprawling suburbs cost more to maintain than more densely packed cities and towns. Stockton and Bakersfield didn’t go under because of too much housing; they went under in part because they spread it too thin. (CNN)
  • Coddingtown Mall is throwing its weight around, demanding that the Coddingtown Station Area Plan leave some streets without bicycle lanes, cut out other bike lanes and new streets that cross mall property, and more, saying they would impose “undue economic hardship” on the property. (Press Democrat)
  • Napa County has a new director of transportation and planning. Kate Miller’s resume is thick on more urban experience, running AC Transit and working for MTC, and here’s hoping that will translate into better service for the Valley. (St. Helena Star)
  • When Caltrans wants to improve air quality in Los Angeles, it doesn’t turn to transit, it turns to wider roads. (Bay Citizen)

The Toll

  • A 37-year-old cyclist died in Santa Rosa after a driver hit him at an intersection. He’s the fifth bicyclist to be killed in Santa Rosa this year. (Press Democrat)
  • Sonoma: A very intoxicated driver seriously injured himself and a man standing in the shoulder of Highway 116. (Press Democrat) … A driver ran off a cliff and survived. (Press Democrat) … A driver was beaten and his car was stolen after a minor fender-bender in Santa Rosa. (Press Democrat)
  • Marin: Two motorcyclists riding at around 100 miles per hour collided, seriously injuring one another. (IJ) … The plaid-hating Tiburon driver apparently also hates bicyclists. (IJ) … A woman drove off Highway 101 and injured herself. (IJ)
  • The toll this week was one person killed, six people injured, and one person beaten.