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Transportation Conformity Domestic Scan Report: Use of Latest Planning Assumptions and Transition to MOBILE6

Appendix E - Feedback from the Domestic Scan Members

Regina Aris
Baltimore Metropolitan Council

Participating on the Conformity Scan team allowed me the opportunity to understand the issues in greater depth and meet knowledgeable individuals that can be a resource in the future. Also of significance was the creativity of MPOs in collecting or identifying data; there are productive partnerships that reduced the cost of accessing data. Finally, sharing what we learned through a report on the FHWA website allows many others to benefit as I did.

Eddie Dancausse
FHWA NC Division

Being a team member on the conformity domestic scan project (CDSP) has been one of the best learning/training opportunities that I have had in my 3 years of work with FHWA and the air quality (AQ) conformity business. The CDSP provided me the opportunity to visit and explore how 6 different States/Metropolitan Planning Organizations dealt with AQ conformity and the processes/tools that contributed to successful conformity determinations. The CDSP also allowed me to establish contacts with transportation/conformity professionals and has opened up a network of individuals that I can consult with on future AQ issues.

Spencer Stevens
FHWA PA Division

It was enlightening to see that the struggles we have with Air Quality conformity in Pennsylvania are similar to those faced in the other scan sites. I now have a much better understanding of the interagency consultation process as it is performed in other regions, and was pleased to see a correlation between the intensity of consultation sessions to the severity of the air quality nonattainment in the region. While Pennsylvania has some air quality issues, ours are not so severe that bi-weekly consultation meetings are warranted.

One of the scan sites in particular struck a cord with me. I have already scheduled an FHWA funded peer exchange for the two MPO directors we spoke with in Tampa, FL to attend our annual Pennsylvania Fall Planning partners conference to speak about their collaborative and cooperative approach to transportation planning. I was struck by the fact that this mega region sees itself as a grouping of smaller MPOs sharing one travel demand model, one air quality conformity model and collaborative data collection. I hope to bring this type of regional thinking back to Pennsylvania.

Charles Baber
Baltimore Metropolitan Council

Participated in the air quality data scan of the Dallas and Atlanta MPOs. At both locations, observed that communication and cooperation between MPO staff, local, state and federal agencies provided for effective technical and policy decisions in determining conformity. In Dallas, this was accomplished in the use of a joint letter between local and state agencies submitted to the federal agencies describing the technical method and assumptions in the upcoming conformity analysis. In Atlanta, greater communication between project sponsors, MPO staff and the state air agency are taking place to ensure consistent use of planning assumptions in SIPs and conformity determination.

Both locations at the time were still in the early stages of understanding MOBILE6 and were not required to conduct a conformity analysis using the MOBILE6 software for a two year period. Dallas was interested in understanding the sensitivity of the various inputs and would concentrate on developing local inputs on the more sensitive assumptions. Atlanta appeared to be relying more on the state air agency in the development of emission estimates using MOBILE6.

Dallas maintained and analyzed an extensive list of Transportation Emission Reduction Strategies (TERMS). It was my understanding that the state air agency considered the implementation of programmed TERMs in the establishment of the mobile emission budget in the SIP. TERMs related to non-recurring delay are credited in the conformity analysis. This credit is used to offset emissions associated with non-recurring delay which is estimated to be 50 percent of recurring delay.

Atlanta uses the land use model DRAM/EMPAL in the forecasting of demographic data at a super zone level and a Zone Allocation Program (ZAP) to distribute the estimated demographic data at the TAZ level used in transportation and air quality planning. Atlanta had just finished a major update to the travel model and provided documentation of the validation.

Kip Billings
Wasatch Front Regional Council

In addition to the information gained for the Conformity Scan best practices report, the visits to other urban areas gave me an opportunity to learn how different agencies deal with some of the same issues faced by the Wasatch Front Regional Council in regards to travel modeling and air quality conformity. By comparing the methods for travel modeling and conformity analysis employed by WFRC with those of other areas I was able to identify some points where WFRC could improve its process and other points where I found that our methods appear to be very much state of the practice.

Accident data - One very helpful emissions modeling tip I picked up was the use of accident data to identify the percentage of vehicles traveling in the non-attainment area from counties that do not have an emissions testing program. This tip was discovered during our visit to Harrisburg, PA. Our emissions modeling has undergone some criticism for omitting this detail. In the past our position has been that the influence on total emissions is small and data to document it is not readily available. It may still be true that the impact is small, but available accident data by county is a fairly convenient means to estimate the percentage of vehicles not subject to emission testing. WFRC will incorporate this detail into future emission modeling efforts.

Limited TIP updates - The Nashville MPO has been successful in limiting conformity analysis to Plan updates. Conformity analysis for the TIP is then a simple matter of identifying TIP projects as those coming directly from the Plan. Nashville has been successful with this simplified TIP conformity not only in the first year of the plan, but also the second and third years until a new Plan is required. This is evidence of good planning and cooperation with other state and local transportation agencies. WFRC would like to imitate this practice and get away from our current habit of amending the TIP more frequently than once per year and amending the Plan more frequently than once every three years.

No TCMs in SIP - It was reassuring to discover that each area we visited had a firm policy similar to that at WFRC of not including Transportation Control Measures (TCMs) in the SIP. The reasons for this policy were also similar to those expressed by WFRC. Including a TCM in the SIP carries a heavy legal commitment that the TCM must receive priority funding and must remain on schedule. The benefits of a TCM can just as easily be achieved but with greater flexibility by identifying them in the TIP or Plan as needed.

Conformity automation - Some of the areas we visited rely on time consuming and error prone manual processes to prepare and process data for the conformity analysis. Some areas reported that conformity analysis takes weeks or even months to complete. The exception may be Pennsylvania where they have developed, through a private contractor, the ability to prepare Mobile6 input files using software prepared for Pennsylvania which prepares the needed input files from the travel model data. WFRC has developed similar though less sophisticated procedures to accomplish this same Mobile6 data preparation task.

MOBILE6 detail - WFRC has also had the good fortune to work with early drafts of the Mobile6 model and was able to use that time to prepare in-house software that prepares Mobile6 input files directly from the travel model data. In doing this, WFRC has taken full advantage of the increased detail available in Mobile6 VMT profiles by speed category, hour, and facility type. Some of the areas visited during the scan are applying Mobile6 default values or are merely using limited Mobile5 data processed in Mobile6 format. For example, in some cases a single speed value used in Mobile5 is represented as a "profile" of two or three speed bins in Mobile6. These procedures are acceptable in Mobile6 but hardly take advantage of the new capabilities of Mobile6 which will ultimately make this model more accurate, faster to use, and easier to defend.

Updated: 07/06/2011
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