Regional Emissions Impact of the CDTC TIP

 

 

Background

 

CDTC developed its first long-range transportation plan and adopted it on March 31, 1981.  Routine amendments and updates have occurred since that time through incorporating recommendations from sub-regional studies, corridor studies, and NYSDOT project development work.  The New Visions 2021 Regional Transportation Plan is a major update to that previous work.  New Visions focuses on travel conditions and needs in the year 2015 and 2021.  The CDTC 2001-06 Transportation Improvement Program is consistent with the New Visions plan.

 

In accordance with the Clean Air Act Amendments of 1990, the U.S. Environmental Protection Agency (EPA) designated the Capital District area as a marginal non-attainment area for ozone pollution in 1991.  This designation was based on the fact that national ambient air quality standards were exceeded at all three Capital District monitoring sites at some time during the three-year period 1988-90[1].  The Capital District has not been in violation of the National Ambient Air Quality Standards (NAAQS) for ozone since 1989.

 

As a marginal non-attainment area[2], the Capital District must show conformity of the Regional Transportation Plan with the Clean Air Act Amendments of 1990, and must abide by actions set forth in an approved State Implementation Plan.  Until a new SIP can be prepared and approved, conformity of transportation plans and programs must be based on analysis of the potential impacts of plans, programs, and projects on air quality.  CDTC used the methodology developed cooperatively by the New York State Department of Transportation and the U.S. Environmental Protection Agency.  CDTC's draft Plan, New Visions for the Capital District, was found to meet the requirements established by the 1990 amendments to the Clean Air Act regarding the conformity of transportation plans.  As demonstrated in the following narrative, emission levels of volatile organic compounds (VOCs) and nitrogen oxides (NOx)-- the precursors to ozone formation-- are less for the plan build scenario than for the 1990 base year.

 

The methodology used to evaluate air quality impacts of the TIP was developed cooperatively by the New York State Department of Transportation and the U.S. Environmental Protection Agency.  Using this methodology, the CDTC 2001-06 TIP was found to meet the former requirements established by the 1990 amendments to the Clean Air Act regarding the conformity of transportation plans.  As demonstrated in the following narrative, emission levels of hydrocarbons and nitrogen oxides (NOx) -- the precursors to ozone formation -- are less for the TIP "build" scenario than for the "no-build" scenario.

 

 

Methodology Used to Model the Emission Impacts of the TIP and New Visions

 

The methodology that was used is described in the January, 1994 NYSDOT memorandum, Proposed Transportation Improvement Program Conformity Determination Process Based on EPA's Final Transportation Conformity Rule.  In accordance with these guidelines, regional emissions estimates were generated by using EPA's Mobile Model 5B software for 1990 (base year), 1996 (plan year), and "no-build" and plan "build" scenarios for years 2006, 2015 and 2021.  These regional emissions rates were updated by the New York State Department of Environmental Conservation using EPA's Mobile Model 5B software in year 2000.  The estimates of emissions were based upon the most recent population, employment, travel, and congestion information developed by the CDTC staff for the four counties.

 

The calculation of base year (1990) travel and congestion data (VMT and speed) for the four county Capital District regional highway network was derived from CDTC's Systematic Traffic Evaluation and Planning (STEP) model.[3]  Using TMODEL2 software, the regional STEP model directly generated PM peak hour VMT and speed data attendant to existing land use, traffic, and highway network conditions.  Twenty four-hour estimates were generated by factoring the PM peak hour trip set in accordance with NYSDOT’s guidelines.  For this exercise, the factor used to adjust the trip set was derived from hourly traffic distributions at more than 100 locations in the Capital District.

 

In order to evaluate the impact of the TIP on emissions, the impacts of a “no-build” scenario were evaluated.  The no-build scenario is a hypothetical scenario that would result if the TIP were not implemented.  The networks used for the 2006, 2015 and 2021 “no-build” scenarios assume projects in the TIP would not be implemented.

 

Travel demand for the year 2006, 2015 and 2021 "no-build" scenarios was simulated using Capital District Regional Planning Commission (CDRPC) official forecasts of households and employment, and CDTC forecasts of vehicle ownership.  These forecasts are documented in the CDTC reports, Forecasts of Regional Traffic Growth for Use in the Year 2000 Needs Estimate, November 1, 1989 and Analysis of Year 2000 Congestion Levels in Critical Corridors of the Capital District, October, 1993.

 

The year 2006 TIP/Financially Constrained Plan network includes projects scheduled in the five year TIP period; the year 2015 and 2021 TIP/Financially Constrained Plan network includes all TIP projects, including those scheduled in the post 5 year period of the TIP. For build conditions for years 2006, 2015, and 2021, travel demand forecasts were prepared that were consistent with achievements expected from implementation of the New Visions plan.  With full implementation of the New Visions plan, increases in daily vehicle travel will be dampened from the trend forecast of 30% (1996-2015) to approximately one-third to one-half that level.  This will occur through a combination of substitution of communication for travel, increased carpooling, increased bus, bike, and/or walk travel, and shorter trip lengths (due to proximity of activities).  This dampening of daily vehicle travel was represented in the CDTC STEP model as a 10% reduction in vehicle trips in 2006 with respect to trend growth forecasts, and as a 15% reduction in vehicle trips in 2015 and 2021.  The full New Visions Plan network for 2015 and 2021 includes TIP projects plus additional economic development and congestion management projects; hypothetical, representative projects were selected which do not have status in the New Visions Plan.  The New Visions Plan intentionally does not designate the additional $60 million for Congestion Management projects and the additional $60 million economic development projects to any specific projects at this time.

 

The financially constrained plan is based on "steady-state funding".  Steady state funding is the currently expected state, federal and local funds would continue at current levels (adjusted for inflation) through the 20-year period, and all federal demo project funds would be received.  This scenario makes comparable progress across all plan improvement initiatives.  The financially constrained plan is assumed to achieve comparable progress -- 71 percent -- in the reduction in travel that would be achieved by full plan implementation.

 

The TIP network used in the analysis assumes that all TIP projects are implemented.  All non-exempt projects were modeled, as well as a number of exempt projects that will affect intersection capacities. Projects programmed in the post five-year network were not included in the year 2006 TIP network, but were included in the year 2015 and year 2021 build networks.  In addition, the year 2015 and 2021 full plan scenario was modeled that includes TIP projects plus additional economic development and congestion management projects, as well as VMT reduction that would result from the full implementation of the New Visions Plan. 

 

EPA's Mobile Model 5B emission rates for volatile organic compounds and NOx were applied on a link by link basis using speed and VMT estimates developed in the STEP model for each scenario.  VMT was increased by ten percent in all scenarios to reflect summer traffic volumes, since the highest levels of ozone are usually detected in the summer months. The Mobile Model 5B emission rates reflect the most current New York State SIP proposals for upstate non-attainment.

 

 

Air Quality Impacts of the TIP and the New Visions Plan

 

Table 6 presents the results of the emission modeling of the 2001-06 TIP and the New Visions Plan impacts. Table 6 indicates that although vehicle miles of travel are forecast to increase in the Capital District between 1996 and the year 2021, hydrocarbon and nitrogen oxide (NOx) emissions will be reduced under all scenarios.  Reduced vehicle emission rates are the primary cause.  Compared to the “no-build” scenario, VOC and NOx emissions will be reduced by the 2001-06 TIP by 2006, and further reduced by the Full Plan Implementation.  The analysis demonstrated that full implementation of the New Visions Plan would result in the lowest emissions of any scenario tested.

 

 

Conclusion

 

The analysis described above indicates that the CDTC 2001-06 TIP and the CDTC New Visions Plan satisfactorily meets the requirements established by the 1990 Clean Air Act Amendments regarding the conformity of transportation programs.  The analysis demonstrates that emission levels of volatile organic compounds and nitrogen oxides -- the precursors to ozone formation -- are less for the TIP and plan implementation scenarios in 2006, 2015 and 2021 relative to the "no-build" condition.  These levels are dramatically lower than 1990 or 1996 emission levels.

 

 

Table 6

 

Air Quality Impacts of the TIP and New Visions

 

 

Scenario

VOC Emissions (Kg/Day)

NOx Emissions (Kg/Day)

Daily Vehicle Miles Traveled (Thousands)

Year 1990

52,182

59,954

17,740

Year 1996

55,912

62,234

20,470

Year 2006 No-build

42,152

44,364

25,504

2006 with 2001-06 TIP and Financially Constrained New Visions Plan1

37,553

41,297

23,525

Year 2015 No-build

22,338

18,114

26,581

2015 with 2001-06 TIP and Financially Constrained New Visions Plan1

18,756

16,724

23,739

Year 2015 with full New Visions Plan2

17,565

16,184

22,739

Year 2021 No-build

19,742

12,473

27,773

2021 with 2001-06 TIP and Financially Constrained New Visions Plan

16,564

11,540

24,935

Year 2021 with full New Visions Plan2

15,479

11,149

23,797

 

1.    The “Financially Constrained New Visions Plan” for 2006, 2015 and 2021 includes the TIP network as well as the VMT reduction that would result from the implementation of the financially constrained New Visions Plan. The year 2006 network includes projects scheduled in the five year TIP period; the year 2015 and 2021 network includes all TIP projects, including those scheduled in the post 5-year period of the TIP.  It is assumed that 71% of the VMT reduction of the full implementation of the plan would be achieved by the financially constrained plan.

 

2.    “Year 2015 with full New Visions Plan” and “Year 2021 with full New Visions Plan” includes TIP projects plus additional economic development and congestion management projects, as well as VMT reduction that would result from the full implementation of the New Visions Plan.

 



[1] Determination of the compliance of the ozone standard for the Capital District is based on data collected at monitoring sites located at the Loudonville Reservoir in Albany County, Skidmore College in Saratoga County, and Mont Pleasant High School in Schenectady County.  The compliance status is determined by the most recent three consecutive years of air quality data; non-attainment is designated if the standard of 0.12 ppm (one-hour average) is exceeded three times over the monitoring period.

 

[2] The CDTC area was classified as marginal non-attainment for ozone until June 18, 1998, when EPA revoked the 1–hour ozone standard.  In the intervening 18 months, CDTC has not been subject to regional conformity requirements.  However, the 1-hour standard was again in place as of January 16, 2001, and CDTC’s non-attainment status was again in effect.

[3] Details concerning the regional STEP model and its calibration are contained in a separate document, Systematic Traffic Evaluation and Planning (STEP) Model - User's Guide and Documentation of Applications,  July, 1994.