Author Archives: Sam Levy

Timed Transfers: A Potential Strategy to Maximize Transit Effectiveness

This summer, my internship has enabled me to make great use of the Bay Area Rapid Transit (BART) commuter rail system.  BART maintains a guaranteed timed transfer system between two of its intersecting lines: train arrivals are synchronized to let passengers change trains almost seamlessly.  This not only reduces BART’s operating costs, but also increases convenience for its customers.  Since large-scale infrastructure improvements will continue to cost hundreds of millions of dollars for the foreseeable future and operating costs will continue to climb, implementing a system of timed transfers is a strategy that agencies can pursue to make the most out of their existing facilities and limited budgets.

The clearest customer benefit of guaranteed timed transfers is reliability.  Knowing that your connecting bus or train will be there when you disembark your original transit vehicle provides critical peace of mind, a phrase seldom associated with today’s transportation systems.  As a BART rider, I know that if I need to transfer, it doesn’t matter if my train is running a minute or two late; BART will take me from Berkeley to San Francisco in under 25 minutes.  This allows me to better plan my daily schedule and avoid giving my friends super conservative predictions like, “I’ll be there sometime between 8 and 9.”

Timed transfers also eliminate the “agitated dash” of inter-line travel.  As a rider of the intersecting Green and Silver lines in Los Angeles, I’ve frequently found myself dangerously sprinting down the two story staircase at the Harbor Freeway Transit Station, praying that I don’t see the disappearing taillights of the Silver Line when I reach its platform.  The MacArthur and 19th Street timed transfers on BART, on the other hand, are virtually stress free.  I know my connecting train operator knows that I’m walking across the platform and that he should leave the train doors open for as long as I need (though I’m convinced some BART operators like to close the door on the slowest transferring passenger in a Darwinian-like reminder to hurry up!)

While timed transfers at line termini may be easier to implement (take for example, an empty bus waiting at a commuter rail terminal for an arriving train), it’s transfers midline that have the best potential benefits.  Midline transfers allows passengers on both intersecting lines to utilize the timed transfer as opposed to only one line worth of passengers in transfers placed at line termini.  This means many more passengers (as well as many more origin-destination groups) can capitalize on the timed transfer.

From an agency standpoint, timed transfers can save money.  In BART’s case, in the southbound morning commute, there are two typical origins (west Contra Costa County and East Contra Costa County) and two typical destinations (San Francisco/Peninsula and Alameda County).  Instead of needing four trains to serve these four O-D pairs, the timed transfer lets BART only use two.  This means two less train operators, less rolling stock, and additional line capacity for other services.

In order to maximize the reliability gains from schedule coordination, transit systems require certain characteristics.  First, the individual lines need to be relatively reliable themselves because timed transfers mean that delays in one line affect the other coordinated line.  Second, there should be strong enough demand for all four origin-destination pairs; otherwise, you will be unnecessarily delaying passengers that don’t need to transfer between lines.  Finally, there should be minimal walking distance between transfer points.  This allows agencies to not only standardize the times that operators need to wait for transferring passengers, but also keep passengers from worrying that they may miss their connecting service.  Timed transfers aren’t feasible on all systems, but they can be a great strategy to increase reliability for customers and reduce operational costs for cash-strapped agencies.

Sam Levy is President of the USC Institute of Transportation Engineers

Advertisements

California High Speed Rail through the Pacheco Pass

Part 2 of a series on the potential alignments of California High Speed Rail.

For the past six months, I’ve been working with AutoCad, Google Earth, and the California High Speed Rail Authority’s website with the goal of creating an up-to-date .kml file of the current proposed route for the CHSR, with specific attention to the alternative analysis.  Starting with today’s post, and continuing for the next couple months, I will be presenting the 2010 proposed alignments and analyzing the alternatives that the CHSRA will carry forward.  The purpose of these kml files is not to show the exact route but rather to help gain a general overview of the alignment alternatives and the types of structures necessary for each alternative.

There are only three places on the San Jose-Merced section where the CHSR horizontal alignment has been finalized: first, between San Jose and Morgan Hill; second, the climb out of Gilroy up to San Luis Rey Reservoir; and third, the brief flat section in the San Joaquin Valley from the California Aqueduct to the a few miles east of I-5.  Other than that, there are 32 possible horizontal alignments on the roughly 100-mile segment of the route between Diridon Station (situated above the current station) and a few miles west of Chowchilla.

The CHSRA settled on the SR-87/I-280 aerial approach to Diridon Station after eliminating seven alternatives.  This segment is going to have significant constructability issues due to business displacement and a gigantic aerial structure over both freeways.  The alignment avoids much of downtown San Jose at the expense of the Almaden neighborhood.

The alignment will then descend to run at-grade next to the Caltrain tracks.  The Caltrain tracks, owned by the Peninsula Corridor Joint Powers Board, will need to be shifted east to accommodate the two CHSR tracks.  After the PCJPB ownership ends near Pullman Way in San Jose, the tracks ascend to an aerial structure, staying outside the right of way of the Union Pacific Railroad (UPRR), a national freight railroad that has been understandably reluctant to share their right-of-way with the CHSRA.  The alignment will continue adjacent to the UPRR tracks until Morgan Hill.

At this point, two horizontal alternatives diverge: one takes the tracks along US 101, the other along the east side of the UPRR right-of-way.  These two sections will connect with one of two alternatives in Gilroy: an alternative that runs through and has a station in downtown Gilroy (with an option for a trench), and an alternative that runs east of Gilroy with a station east of the outlet stores on Leavesley Road.  The East of UPRR alignment will require a relocation of the Monterey Highway.  The CHSRA prefers the UPRR alternatives because they follow existing transportation corridors and provides the quickest time between Morgan Hill and Gilroy (8.75 minutes).  The trench option, demanded by the City of Gilroy to reduce visual impacts of an aerial structure, would create a 5-mile, 185-foot wide trench, but would require use of the Union Pacific right-of-way.

The east of Gilroy alternatives are not preferred, but are carried forward because of reduced residential displacements and to placate the City of Gilroy.  Unfortunately, the East Gilroy alternatives would place a station on Leavesley Road.  A station here would not only create a visual impact in this now-agricultural area, but also reduce connectivity with Caltrain and a future commuter rail line to Monterey.

East of Gilroy, the construction team will face “steep terrain, narrow valleys, and engineering challenges.”  In this Pacheco Pass section (chosen over Altamont for a more direct route to the Bay from Los Angeles), bridges in excess of 300’ in height as well as intrusion into the San Luis Reservoir, the San Joaquin National Cemetary, Pacheco State Park, or Mt. Hamilton Nature Conservancy were deemed unallowable.  Using Quantm, a computer model to identify effective alignments, the Authority picked one alignment and a deviation near the San Luis Rey Reservoir (“Close to 152” Alternative).  Both alignments include 8 tunnels, with the longest tunnel being 22,700 feet (4.3 miles) long.

The San Joaquin Valley subsection has been reduced to two alternatives along Avenue 21 and 24 and Henry Miller Avenue.  Avenue 24 has more severe impacts in Chowchilla where the route calls for a wye connecting the Los Angeles and Sacramento branches, but has eight less grade separations and effects 81 less acres of farmland when compared with the Avenue 21 alignment.

The San Jose to Merced section will face significant challenges in working with the Union Pacific Railroad and the cities along the US-101 corridor between Gilroy and San Jose.  The Pacheco Pass section will present some of the most difficult engineering challenges along the entire alignment.

Here is the .kmz file for Google Earth.

CAHSR’s Preliminary Alignment on the Peninsula

Narrow Right-of-Way in San Mateo

For the past six months, I’ve been working with AutoCad, Google Earth, and the California High Speed Rail Authority’s website with the goal of creating an up-to-date .kml file of the current proposed route for the CHSR, with specific attention to the alternative analysis. Starting with today’s post, and continuing for the next couple months, I will be presenting the 2010 proposed alignments and analyzing the alternatives that the CHSRA will carry forward. The purpose of these kml files is not to show the exact route but rather to help gain a general overview of the alignment alternatives and the types of structures necessary for each alternative.

As a native San Franciscan, I thought it would be best to start with San Francisco and head south during this review of the California High Speed Rail alignments. This section has been a major talking point as a part of the entire California High Speed Rail debate. Due to prohibitive costs,the High Speed Rail Authority has been reluctant to bury a significant portion of the alignment,much to the dismay of local communities who fear not only lowered property values, but also the prospect of their communities being “divided in two” by the high speed rail right of way.

Along with the Los Angeles to Anaheim section, this section of the alignment is unique in that,at this point in the design process, there is only one horizontal alignment under consideration;that is, there is only one right-of-way path. In this section, alignment alternatives along I-280 and US-101 were ruled out due to design challenges. An I-280 alignment would have been too curvaceous to allow for the Prop 1A guaranteed 2 hours and 40 minutes between LA and SF and the US-101 path would be too expensive due to the multiple overpasses already in place on the freeway. Instead, the CHSRA chose to pursue the current Caltrain right-of-way as the preferred horizontal alignment.

That is to say, the Caltrain alignment is not without its design challenges. The right-of-way in some parts of the peninsula is only 50’ wide, much narrower than the 91’ expected to be necessary for even the narrowest of high speed rail structures. Downtown San Mateo and Redwood City, in particular, present difficult engineering challenges due to their narrow right-of-ways. As of September 2010, the HSR Authority settled on three designs. Design A includes more aerial structures and is likely to meet the most opposition from Peninsula cities. Design B places many of the aerial structures below grade in trenches or tunnels. Design B1, labeled B1 because it is a variation on Design B, places even more track below grade.

On the corridor, HSR will be sharing the right-of-way and the four tracks with an electrified Caltrain, meaning that the HSR will be restricted to 90mph on the Peninsula. The Authority is also choosing between a possible “Mid-Peninsula Station” in Redwood City, Palo Alto, or Mountain View. Either one or none of these stations will be selected.

You are free to view this map but please know that it is not affiliated in any way with the California High Speed Rail Authority, and Sam only used publicly available information to compile it. If you’d like to share it, please attribute it to Sam Levy or Wilshire/Vermont. He spent a lot of time getting this thing together. -Karl

Enjoy.

Sorry about the ads. WordPress won’t host a .kmz file.

The (Potential) Paradox of California High Speed Rail



At $45 billion dollars, the California High Speed Rail project will be the state’s biggest project in its history.  With a promise of connecting Los Angeles to San Francisco in two hours and forty minutes as well as up to 22 other stations in the state, the project promises to take a significant portion of the market from intrastate air travel between Southern California and the Bay Area.  The California High Speed Rail Authority boasts of 450,000 new permanent jobs, reduced congestion, and cleaner Californian air.

More importantly, however, the project makes the prospect of statewide commuting much more realistic.  The 142-mile trip from Bakersfield to Los Angeles becomes a trip of 54 minutes, several minutes less than the 48-mile Baby Bullet trip from San Jose to San Francisco on today’s Caltrain corridor.  From Fresno in the middle of the Central Valley, it will take a mere 51 minutes to get to Silicon Valley and only a few minutes more to reach Sacramento.

While the project’s potential substantially increases California’s connectivity, there is a danger of creating an even greater exurbia.  The Antelope Valley cities of Lancaster and Palmdale, sitting on the edge of Metrolink’s current network, will no longer demarcate the boundary of commuter sanity.  In other words, the High Speed Rail project will push the limits of how far away we are willing to commute.  While the train promises to be a cleaner commute, should it be a commute we should be making?

For every dollar spent on making intercity commuting more accessible, California should invest in making intra-city commuting easier.  Simply put, more trips, be it by train or by car, are still more trips.  Bakersfield should focus on adding jobs and transit-oriented development in Bakersfield rather than making it easier to get out of Bakersfield.  The authority promises to promote transit and pedestrian development at infill stations, but there still remains a risk of turning the entire Central Valley into heavy-commuting, Palmdale-esque suburban midlands.

By the way, this post was written by Sam Levy, a Civil Engineering colleague of mine from USC. Many thanks to him for the article. -Karl