Committee on Environment and Public Works
FROM: Metropolitan Planning Organization of the Houston Galveston Area
Houston-Galveston Area Council of Governments
1) Differences in Timing of Schedules
There are a variety of problems resulting from the various schedules of the State Implementation Plan (SIP), Transportation Improvement Plan (TIP), and conformity, etc. The Clean Air Act requires a conformity demonstration once every three years, yet numerous other triggers render this requirement irrelevant, for all practical purposes. Under the Environmental Protection Agency’s (EPA) rules, nonattainment areas must demonstrate conformity each time EPA proposes or approves an initial SIP submittal, each time the EPA modifies a control measure that impacts the motor vehicle emissions budget (MVEB), and each time a transportation control measure is added, modified, or deleted. Conformity demonstrations are also needed each time the metropolitan planning organization needs to add or modify a project in its transportation plan (since a road or transit project cannot move forward unless it is specifically included in a conforming transportation plan). This overabundance of conformity triggers means that planning organizations are frequently performing conformity demonstrations, with limited corresponding benefit..
· Describe how the different schedules for the SIP, TIP, conformity, etc. and the impacts of data changes on out year emissions affect your ability to develop effective and timely transportation and air quality plans. An ‘initial’ SIP has been submitted to the EPA from the State of Texas for the Houston-Galveston Area approximately every 12 to 18 months for the past five years. An initial SIP submittal contains a MVEB requiring new conformity analyses and documentation. These frequent submissions have caused H-GAC to spend a considerable amount of time over the past five years conducting analyses and preparing conformity documentation.. The time and resources required to prepare detailed conformity determinations has come at the expense of planning and implementing new transportation and air quality strategies. The latest conformity finding received federal approval in May2002. In order to complete this finding, work was suspended on the more fundamental re-evaluation of the region’s transportation plan due to the time and resource constraints of conformity. Many of the new areas of investigation intended to further reduce vehicle emissions (including major expansion of high capacity transit corridors and exploration of more travel efficient land use development) were delayed.
· What impact have these schedules had on investments in highway and highway and safety projects, construction costs, and air quality projects and activities. For the most part, the region has managed to move its transportation and air quality improvements forward under the current conformity regime. However, as discussed in other sections, the current conformity process has taken away from the time that is needed to update the metropolitan transportaion plan (MTP), delayed some projects due to a conformity lapse, and adversely impacted resources needed to plan and implement air quality projects.What has been your experience coordinating your SIP and conformity processes with SIP submittals and updates? The development of the SIP, Metropolitan Transportation Plan (MTP) and TIP are seldom in alignment. The SIP process is conducted on an independent schedule (with the timing of actions often dictated by the EPA or the courts) without regard to the timing of MTP or TIP development. For example, the Houston-Galveston nonattainment area is now working to develop its new MTP based on soon-to-be completed corridor studies. Because the State does not plan to incorporate the EPA required MOBILE6 emissions budget until late 2003 or 2004, the region’s Transportation Policy Council (MPO governing body) may not be able to formallyact on locally preferred alternatives developed in these corridor studies, due to the MOBILE6 conformity black-out period. The MOBILE6 blackout refers to the period of time that MPOs have to use MOBILE5, one year post-release of the new model or January 29, 2003. However, states have 2 years from the release of the new model to develop a new MVEB creating a one-year window where MPOs may not be able to develop a new plan and required conformity demonstration.
These coordination and scheduling issues could be addressed, in part, through more formally required coordination processes between the states and MPOs.
· Compare and contrast your MOBILE5 and MOBILE6 emission projections. For this section, we are using the Houston-Galveston area (HGA) attainment date of 2007 as the point of comparison for MOBILE5b and MOBILE6. The HGA 2007 MVEB using MOBILE5b was adjusted downward when the NOx budget was set to 156.6 tpd. The adjustments to the modeled results were due to off-model calculations beyond the capabilities of MOBILE5, as well as to programs such as the Voluntary Emissions Reductions Program (VMEPs). Please note that none of the numbers in Table 1 reflect the impacts of the VMEPs. The VOC budget was set at 79.5 tons per day.
Ø Table 1 is a comparison of the MOBILE5b results used by the Texas Natural Resource Conservation Commission (TNRCC) to establish the motor vehicle emissions budget for the attainment year 2007 and the results produced by MOBILE6 using the same regulatory programs. The change in vehicle miles traveled (VMT) is the result of more recent planning data, rather than a change in the MOBILE model. Although there is some consistency in the overall total budgets between MOBILE5 and MOBILE6, there is a significant difference in where the emissions are being generated. MOBILE6 more accurately reflects diesel emissions and better incorporates engine and fuel improvements which result in lower emissions from light-duty vehicles than MOBILE5.
· How does the increase in near term emissions (through 2010) from MOBILE6 affect your conformity status? The focus of the current HGA SIP is on reducing NOx emissions. MOBILE6 leads to lower calculated NOx emissions when compared to MOBILE5b, in spite of a 3% increase in VMT. The new emissions model facilitates meeting the NOx budget in 2007. The same cannot be said for the VOC emissions. Although the VMT is 3% higher, VOC emissions are roughly 8% higher. The current 2007 VOC budget is 79.5 tpd. This number, like the NOx number, is based on MOBILE5b modeling and off-model calculations. Using the MOBILE6 model and the measures currently in the SIP, the HGA could not make the established MOBILE5b VOC budget for the attainment date 2007.
· How will your air quality planning process take the new MOBILE6 into account and will the SIP be updated before or after the new MOBILE6 projections? Currently the state is planning to do a major, mid-course revision to the SIP in 2004. It plans to incorporate MOBILE6 into this revision. This schedule for an updated SIP with a new budget using MOBILE6 is not consistent with the current schedule for updating the MTP. .
· Will the new 8-hour NAAQS likely lead to an increase or decrease in your vehicle emissions budget? At this time H-GAC is unaware of any analysis done on the 8-hour standard or budget for the HGA. The assumption is that the budget will be lower than under the 1-hour standard. Modeling has not yet been conducted to verify this statement.
3) Additional Vehicle Emission Controls
· What additional existing controls could be implemented in your area to significantly reduce vehicle emissions, e.g., inspection maintenance, reformulated fuels, diesel retrofit, TCM? In the HGA, the on-road mobile sector currently has been required to reduce emissions in a greater proportion than the sector contributes in comparison to other nonattainment areas. The on-road mobile portion of the emissions inventory is under great pressure as a result of the region being a severe nonattainment area for ozone, uncertainties regarding precursor contributions from NOx and VOCs in the photochemical model, and additional issues related to the emissions inventory. . The HGA has employed every conceivable on-road emission reduction strategy currently available, except for no-drive days.
· Would these controls be sufficient to address the potential increase in emissions projected under MOBILE6? As mentioned above, the focus of the HGA SIP has been on NOx reductions. The biggest problems anticipated in the utilization of MOBILE6 are as follows:
Ø Light duty vehicles will yield less NOx emission reductions under MOBILE6 than MOBILE5, making current emission reduction strategies (those that target light-duty vehicles), exceedingly more expensive for limited emission reduction benefits.
Ø Measures that target the reduction of VMT under the current plan may have congestion mitigation benefits but limited NOx emission reduction benefits.
Ø Efforts and programming plans for emission reduction strategies may change in priority and focus under MOBILE6, creating uncertainties in implementing the programs.
4) Role of Transportation Control Measures
· TCMs play a very small role in helping to meet HGA’s attainment. The total reductions from the HGA TCMs under MOBILE5 are slightly more than 1 tpd for NOx with roughly 2 tpd for VOC. Using MOBILE6, the HGA TCM reductions for NOx emissions are less than 1 tpd and are roughly 1 tpd for VOCs. TCMs represent 0.1 percent of the SIP’s total reductions. The region is implementing a number of transportation projects that address congestion and also have air quality benefits, but have not been formally committed as TCMs. The cost through TIP year 2004 for these TCMs and other related projects is in the hundreds of millions of dollars. A summary of TCM commitments for the region is listed below.
Signalization 52.2 miles
High Occupancy Vehicle lanes 18.2 miles
Park and ride lots 15,098 spaces
Arterial Traffic Management System 343.48 miles
Computerized Traffic Management System 387.37 miles
Bicycle lanes 435.998 miles
Accident investigation sites 3.2 miles
5) Impacts of Conformity Lapse
From November 1999 until June 2000, the Houston-Galveston region experienced a conformity lapse due to the time required to evaluate its MTP against a new budget for NOx. This lapse delayed design and right-of-way acquisition for several significant transportation projects, including the widening and reconstruction of US 59 South and Interstate 10 West. The lapse occurred because of a change in the interpretation of a post-NOx waiver SIP submittal from a ‘revision’ to an ‘initial’ SIP with an MVEB. The MVEB was submitted a month after the SIP and had been interpreted by the conformity consultation committee as a revision. EPA staff made an interpretation that the budget was an “initial” submittal in the Rate of Progress SIP submission by the State of Texas to the EPA. Notification of this interpretation was not received in time for the MPO staff to conduct a new conformity determination prior to the November lapse deadline.
6) Role of Motor Vehicle Emissions Estimates and Models
· How has conformity analysis helped improve the quality of estimates of
motor vehicle emissions for SIPs to better protect public health? Both the development of MVEBs and transportation conformity require a level of detail and precision that is inconsistent with real world experience, and the capabilities of travel demand estimation and mobile emission models. However, the on-road emissions estimates are probably the best evaluated portion of the total emissions inventory. Due to the requirements of ozone models, much more data has been collected and evaluated to determine hourly VMT, vehicle speed, vehicle type and age distribution. The value of this information to public health must be tempered by the fact that other significant portions of the ozone forming emissions inventory are poorly measured, particularly emissions for aircraft and most off-road and marine vehicles. The EPA’s new MOBILE6 emissions model suggests that heavy-duty trucks play a disproportionate role in NOx emissions production. The analysis and measurement of freight travel is traditionally one of the weakest areas of urban travel forecasting. HGAC has attempted to develop specific data for truck origins and destinations for major generators, such as its ports and airports.
· How accurate and consistent have estimates of regional motor vehicle emissions been when compared with each other over time and with actual experience? Although the primary travel inputs to motor vehicle emissions estimates (vehicle miles of travel, vehicle speed and vehicle mix) have been relatively consistent over time, the estimate of motor vehicle emissions has been radically altered by revisions to EPA’s mobile source models and modeling procedures for control strategies such as vehicle inspection/maintenance programs. Because of the revisions to EPA’s MOBILE models, it is unlikely that any area’s emissions estimates from the early 1990s for 2005 or 2007 would resemble those made today.
· How have official estimates of motor vehicle emissions in your metropolitan region changed over the past 10-20 years and how well have they tracked actual emissions in years past? They have increased mostly because of changes between MOBILE models. On-road emissions have increased on a gram/mile basis with the release of each model since MOBILE4 (VOC nearly doubled between MOBILE4.1 and MOBILE5a-h). Economic cycles also play a major role in changing on-road budgets, since fleet ages change rapidly in strong economic cycles.
7) Roles of Transportation Models
· Adequate regional transportation analysis models have supported the conformity analysis. These models accurately reflect how changes in highway capacity affect total travel, travel speeds, travel paths and resultant air pollution emissions (to the extent the EPA emissions models have revised emissions rates, the emissions estimates may vary).
· The region’s travel models have tracked reasonably well the growth in VMT. As compared to forecasts made in the late 1980s or early 1990s, the sustained economic growth of the 1990s has required upward revisions in future year population and employment estimates, which subsequently have increased future year travel estimates.
· The regional travel models are sensitive to traffic changes that are induced by changes in travel patterns in the region.
· Transportation conformity determinations should only be required once every five years. Currently, full transportation conformity determinations are required each time the EPA or the State proposes or approves an initial SIP, each time the EPA or State modifies a control measure that impacts the motor vehicle emissions budget, and each time a transportation control measure is added, modified, or deleted. Conformity determinations are also currently required if the planning organization needs to add to or revise a transportation project in the transportation plan (since road and transit projects cannot generally proceed unless they are specifically included in the plan).
· Amend TEA-21 to require MTP, TIP, and SIP updates not less than every five years with the transportation conformity rule applying after each five-year SIP update requirement is met. If a more frequent update of the TIP is needed, as is often the case today, this would be allowed using the same assumptions used in the most recent transportation plan and SIP.
· The newly released MOBILE6 emissions factor model further exacerbates this situation. MOBILE6 has not been used at all in SIP development and there is no requirement to update SIPs using MOBILE6 prior to using it for conformity determinations. Regardless, transportation conformity determinations must use this model within 24 months.
· Planning organizations should have the ability to add or modify a road or transit project and TCMs (to some degree) without the need for a full conformity demonstration. Currently, planning organizations must go through a full conformity analysis to make minor changes. This exercise is unnecessary and a waste of valuable local, state, and federal resources.
· Encourage TCM substitution without a SIP revision, so long as equivalent emission reductions are forthcoming from other measures. Such a substitution would not trigger a new conformity determination. A model for such a process might be the Emission Budget Adequacy process used by the U. S. EPA, if expanded to address outdated, but currently approved, SIP budgets.