MTA provides some Red Line answers
Last week I wrote that opponents of the proposed Red Line had raised some pertinent questions that deserved answers from the Maryland Transit Administration.
One had to do with revised ridership projections in the plan Gov. Martin O'Malley chose for the so-called "locally preferred alternative," which came in about 28 percent higher than in the draft environmental impact statement. That revision helped bring the project within federal cost-effectiiveness guideline so that it could qualify for 50 percent U.S. funding. Red Line foes have implied that the magnitude of the change suggests the MTA had been cooking the books to get that result.
The other has to do with the decision to go with a single track in the one mile of light rail tunnel to be built under Cooks Lane. Opponents raiised the spectre of a catastrophic head-on, high-speed crash in the tunnel.
I put both questions to Henry Kay, the MTA's deputy administrattor for planning, during an interview last week.
On the revised numbers, Kay said the environmental statement relied on 1996 data because those were the most recent available at the time. He said the final plan relied on data from a 2007 on-board ridership survey.
Among the changes found in the newer survey, Kay said, were a siignificant increase in the number of people living in downtown Baltimore and a greater concentration of households without autos than was reflected in the older data. Both findings increased the number of potential riders, he said. Kay further noted that the Baltimore Metropolitan Council has, since 1996, revised its forecast of population and households in the region.
Kay said the MTA has been checking its methodology with the Federal Transit Administration continuously through the process and is confident it will stand up to the agency's scrutiny.
"It would be very foolish of us to publish numbers and recommend a locally preferred alternative we've not (had) vetted by the agency that will actually provide funding," Kay said.
On the single-tracking, Kay agreed it is not the ideal configuration for the Cooks Lane corridor. But he insisted that single-tracking a portion near one end of the line can be done safely and without serious delays.
Kay said trains can share a single rack as long as there is in place a well-desgned signaling system. He noted that the current Central Light Rail system include a singe-tracked segment near the north end of the line that has never has a head-on collision.
The MTA officials said any such system would include multiple levels of safeguards, including protocols for human operators and an electronic "trip stop" system.
Kay said it is by no means sure that the Red Line would eventually operate with a single-track tunnel, He said that if ridership numbers or funding levels increase, such a move might not be necessary.
I asked Kay aboout some of the MTA's previous statements about single-tracking when it came under pressure from some Montgomery County Council members to consider that option along three miles of the Purple Line in order to save more trees from being cut down.
The MTA wrote:
In sum, introducing a single-track segment between Bethesda and Connecticut Avenue would significantly compromise travel time savings, service frequency, passenger carrying capacity, and the maintenance and operating reliability of the Purple Line, thereby reducing the effectiveness, efficiency, and the return on a $1.3 billion investment. The reduction in the amount of tree clearance hoped for from building a trail and single-track segment would not likely be achieved. For the many reasons stated above the MTA strongly recommends against single-tracking any portion of the Purple Line.
To some, this is evidence proving that the MTA is saying one thing in suburban Washington and another in Baltimore. But Kay said the circumstances are not comparable.
"What's different is the setting," he said.
Kay said the segment the where the Council members were interested in preserving trees was 3 miles and included a station. That, he said, would have created more operational difficulties than the 1-mile stretch under Cooks Lane, which would not include a station. What Kay did not say, but I will, is that there's a big difference between accepting single-tracking to accommodate a few trees and doing the same thing to make a project viable.
It should be noted that the reasons the MTA cited for opposing single-tracking on the Purple Line did not include safety. So no inconsistency exists on the most important issue raised by the single-track plan. I don't see a smoking gun here.
I don't expect these answers to change minds on either side of the Red Line issue, but I thought they belonged on the record.
It seems to me there's not much point stressing over the ridership estimate. Those numbers will soon be in the hands of the FTA, and they will either pass muster ot they won't.
The single-track issue is more serious. The burden is on the MTA to show it can design a signaling system that can defeat Murphy's Law: the proposition that anything that can go wrong will. And it will have to make its case in a way that legislators and other lay persons can understand.
Comments
I don't think it is so easy to write off the ridership issue. The original 1996 data was carefully analyzed and the initial Baltimore Regional Transportation Board revision of the travel demand model based on that data was run through public review and comment. Since then, the MTA tinkered with the model, but they were required to record information in their Draft Environmental Impact Statement technical reports. Where are the more recent revisions recorded for public review? And, more digestible for those of us who are not so technically astute, what is the accuracy of the model at predicting current ridership? The old model was horrendous when compared to reality: it underestimated transit trips originating in the Central Business District by 26.3% and Metro Subway trips by 17.5%, etc., etc. I'm all for improving it--but when will the public see the accuracy data on the new model to see if it really was improved?
One other question is raised by the use of a new model--or at least new calibration data--mid-project: what of the alternatives rejected because their ridership was too low relative to costs? Will they be reconsidered? Or is this revision only for the selected alternative? This question leads to the fundamental of problem of travel demand modeling in the New Starts process (at least the one Baltimore follows): travel demand modeling is an inherently imperfect science, and thus by building a travel demand model to analyze a particular project rather than to analyze a system, the MTA has the flexibility to create a model that serves their needs in this one instance. That is an unhealthy way to analyze alternatives. It because even less "scientific" and becomes overtly political, defeating the very purpose of the cost-effectiveness standard.
Posted by: Saul Wilson | August 11, 2009 8:16 PM
I'm not at all convinced that the reasons cited by Kay you mentioned are the defining factor in the ridership changes. Baltimore transit ridership in total rides hasn't changed that much between 1996 and 2007, even though travel patterns may have. Moreover, given the fact that the LPA is slower than 4C even though it has 2 fewer stations means the bias is likely above 30%. I suspect that some key coefficients have changed, such as gas prices relative to pass prices. This is a great example of how hard it is to predict much of any kind of human behavior far into the future other than the need for food and water. We'll see how this plays out. Too bad for all the projects who short changed themselves by applying a year too early ;). Overall, Saul’s points above dovetail with the points I’ve made here and elsewhere and truly need adequate explaining and validation to maintain any integrity for a cost-effectiveness figure. I emailed project management and made a phone call to get the detailed information. On Friday, I heard that the MTA had intended to have released the critical material by the end of that day, but wouldn’t get it done in time and was hoping for early next week. Still nothing. What’s the hold-up? Most of this information could have been released immediately.
As far as the Deathtrap tunnel, I want to know who has a single-track tunnel and why the MTA wants to be unprecedented on the wrong things. I read the Purple Line document and I think the point is still cogent and significant even if the length is shorter.
Nate Payer
TRAC
Posted by: Nate | August 12, 2009 7:06 PM
The FTA rider model undercounts rail but overcounts bus ridership. That is for sure.
The single track tunnel is NO problem. A
mile takes only two minutes one way, so a 7.5 minute headway will work reliably if scheduled to avoid conflict. Safety is assured by automatic train stop signals
and could have derails for violations. Single track is all over the country on rail-
roads which are very safe.
Posted by: Ed Tennyson | August 12, 2009 11:05 PM