Page 1 of 8 May 25, 2012 TO: Board of Supervisors Andrew Beacher
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COUNTY OF LOUDOUN, VIRGINIA TRANSMITTAL MEMORANDUM DATE: May 25, 2012 TO: Board of Supervisors FROM: Andrew Beacher, Director, Transportation Services Ben Mays, Acting Director, Management & Financial Services RE: Responses to Supervisor Reid’s Metrorail Questions Submitted 4/30/12 CC: Tim Hemstreet, Linda Neri, Charles Yudd, John Sandy, Leslie Hansbarger, Julie Grandfield, Danny Davis, Anna Nissinen 1. In the DESMAN Traffic study, it states that The Dulles Corridor Rapid Transit Project Final Environmental Impact Statement (FEIS) for the full Locally Preferred Alternative (LPA)1, was published in 2004, using the Northern Virginia Major Investment Study Model with inputs from the Metropolitan Washington Council of Governments (MWCOG) Round 6.3 Cooperative Land Use Forecasts representing year 2003, as well as future highway and transit networks, transit operating plans developed for the project and operating characteristics of the Dulles Toll Road. It also states, as Mr. Pant told us April 17, that there was no up to date modeling or traffic forecasting data. Is it not true that this Northern Virginia Major Investment Study model is not the official COG forecasting tool? Why didn’t DESMAN use the COG Model, which is now Version 2.3 (calibrated and approved in 2011)? As part of the development of the Environmental Impact Statement (EIS) process, the Northern Virginia Major Investment Study (NVMIS) model was selected to model travel demand in the Dulles corridor. As described in Chapter 3 of the June 2002, Travel Demand Forecasting Methodology and Results Report (Attachment 1) that accompanied the Draft Environmental Impact Statement (DEIS), this model was judged superior to the COG model available at that time. Transportation models are designed to reflect best practices for the particular project at hand. While regional models such as the one COG maintains are used to assess overall regional transportation conditions that then feed into forecasts of air quality, subregion outputs are generally only used at the level of an entire road corridor or metro line. Adaptations of COG models are used for project planning studies, and include refinements designed to enhance the accuracy of modeling for the project being studied. COG staff did provide “off-the-shelf” transit boarding data via a memorandum to DESMAN in January 2012, as shown on the handout provided at the May 16 Board worksession. This data was produced running the Version 2.3 model, and using forecasts for the traffic analysis zones (TAZs) within a one-mile radius of the proposed Rt. 606 and Rt. 772 stations. Daily boardings at the Rt. 606 and Rt. 772 stations were summarized from the Version 2.3 model outputs using land use projections reflected in the Round 8.0a Cooperative Forecasts. COG’s memorandum has a caveat, which includes a discussion of the model’s applicability to the station level: “The Version 2.3 model has not been validated to the individual station level, let alone at the mode of Page 1 of 8 COUNTY OF LOUDOUN, VIRGINIA TRANSMITTAL MEMORANDUM access level to each station. The time allotted for model calibration work did not allow for such level of rigor.” As indicated by COG staff, the Version 2.3 total daily boardings for the Silver Line as a whole are essentially the same as the FEIS forecasts (1.5% higher) for year 2025. COG staff goes on to say that the station level boardings do not compare as well and without further analysis it is difficult to explain why differences exist. “TPB staff speculates that the FEIS boardings figures were refined after initial modeling results were analyzed. The Version 2.3 forecasts are ‘raw’ and have not undergone any such refinement. Land use differences between Round 6.3 and Round 8.0a are, of course, another potential cause of variation. The difference in TAZ systems underlying the transit network is another important factor to consider.” There are several reasons to use the station boarding data in the FEIS rather than the COG data: DESMAN believes the level of rigor, analysis and specificity is greater for station-level boarding data in the FEIS than the data provided by COG; Since the line level data produced by Version 2.3 is consistent with the line level data in the FEIS, the best available station boarding data should be the refined station boarding data included in the FEIS; and The model used in the FEIS was specific for the Metrorail extension and the output has been refined, whereas the Version 2.3 model is a regional model not specific to the Metrorail extension. 2. When calculating ridership it appears that the DESMAN study does not use a model, but rather they extrapolated ridership by dividing the projected boardings by the number of projected households from the FEIS in 2025 and then multiplying that ratio by the number of projected households from other years in other various studies. Does staff consider this a sound methodology? In order to forecast daily station boardings, DESMAN’s methodology determines boardings per household: (1) As a commuter transit link, it is reasonable to assume that the majority of daily boardings (83%) will be typically comprised of home‐based commute trips and will in turn be directly related to the number of households producing those home‐based work trips. As a result, a mathematical relationship can be drawn between number of households and boardings, and used to forecast boardings for other years. (2) The FEIS provided only one year (2025) of boardings for the new stations. Using that data as well as MWCOG’s Round 6.3 household data for the same year, DESMAN established ratios for each station (Rte 606 and Rte 772) by dividing the number of households forecasted from Round 6.3 into FEIS’s forecasted number of boardings at both stations in year 2025. Page 2 of 8 COUNTY OF LOUDOUN, VIRGINIA TRANSMITTAL MEMORANDUM Staff considers that this methodology is based on the professional experience and judgment of DESMAN. 3. It says in one of the DEIS documents that it measures non work trips and estimated ridership based on TOD, is that correct? Per MWAA, the ridership forecasts presented in the Draft EIS included all projected transit trips (work and non-work) and were developed using regional population and employment forecasts prepared by the Metropolitan Washington Council of Governments (MWCOG). The MWCOG forecasts are based on inputs from local jurisdictions on future land uses and allowable development. All data presented in the Draft EIS reflect the approved growth forecasts prepared by MWCOG. As noted in the Draft EIS, a sensitivity analysis was also conducted to estimate potential Metrorail ridership in the Dulles Corridor under a rail-related development scenario (higher densities and alternative land uses at station areas). This analysis projected that the base ridership levels presented in the Draft EIS would increase by approximately 15 percent under a more intensive development scenario. 4. The 2003 data that this was based on – is that based on downzoning of Loudoun or pre- downzoning, in which case there would be more by right development in the West and thus more households – perhaps 50,000 more households? The Final Environmental Impact Statement (FEIS) used Round 6.3 forecasts. Round 6.3, from 2003, was the first set of forecasts to reflect the land use changes shown in the Revised General Plan. The Revised General Plan, which was adopted in July 2001, included a reduction in the number of residential units that could be built. 5. To what do you attribute the difference in the projected ridership in 2025 for the two Loudoun stations from the Draft Environmental Impact Statement to the Final EIS? The DEIS estimated that boardings for the two Loudoun stations will be: 4,867 at 606 and 1,492 for route 772. The FEIS projects 4,485 at 606 and 6,961 at 772? What caused the difference? Per MWAA, the primary cause was the change in the location and amount of parking available at each station. At the request of Loudoun County, the amount of new parking the Route 606 station was reduced (from 4,000 to 2,000 spaces) and the amount of parking at Route 772 was increased (from no spaces to 3,300). The other factor was the use of a newer version of the MWCOG Cooperative Forecasts (Round 6.3) for the Final EIS ridership estimates (the Draft EIS estimates used Round 6.2). 6. When these studies refer to “boardings” that counts both entrance and exit at the station correct? So generally speaking each commuting rail rider will represent two boardings? One boarding represents each time a person gets on to the train. One alighting represents each time a person exits the train. Page 3 of 8 COUNTY OF LOUDOUN, VIRGINIA TRANSMITTAL MEMORANDUM 7. The study done in 2005 by the Washington Airports Task Force used a more recent land used forecast and the COG Model. The study shows ridership of 2,200 at 606 and 2,200 at 772 in the year 2030. I would like to add that this study was conducted by a reputable modeler named Bill Allen who was hired by WATF to do the study. What do you make of this and were you not aware of it before commissioning DESMAN to do its analysis? Please see the response to question #1 for information on the limitations of the use of the COG regional model, without adaptations, for projecting station boardings. 8. WMATA in its April 17 handout said it saves the Washington region some $350 million in auto- related expenses, but if the subsidy is well over $650 million, does not this mean that the region is not saving anything, and in fact, is losing $300 million each year? WMATA used calculations presented in its “WMATA: Making the Case for Transit, November 2011 Edition.” On page 6 of that report, WMATA presents its fourth point for making the case: “4.