Section R18-2-1430. Procedures for Determining Regional Transpor- tation-related Emissions

A.      The following are general requirements for determining regional transportation-related emissions:

1.        The regional emissions analysis for the transportation plan, TIP, or project not from a conforming plan and TIP shall include all regionally significant transportation proj- ects expected in the nonattainment or maintenance area, including FHWA or FTA projects proposed in the trans- portation plan and TIP and all other regionally significant transportation projects which are disclosed to ADOT or the MPO as required by R18-2-1405. Projects which are not regionally significant are not required to be explicitly modeled, but VMT from such projects shall be estimated in accordance with reasonable professional practice. The effects of TCMs and similar projects that are not region- ally significant may also be estimated in accordance with reasonable professional practice.

2.        The emissions analysis may not include for emissions reduction credit any  TCMs which have  been delayed beyond the scheduled date until such time as implementa- tion has been assured. If the TCM has been partially implemented and it can be demonstrated that it is provid- ing quantifiable emission reduction benefits, the emis- sions analysis may include that emissions reduction credit.

3.        Emissions reduction credit from projects, programs, or activities which require a regulation in order to be imple- mented may not be included in the emissions analysis unless the regulation is already adopted by the enforcing jurisdiction. Adopted regulations are required for demand management strategies for reducing emissions which are not specifically identified in the applicable implementa-

Department of Environmental Quality – Air Pollution Control

	tion plan, and for control programs which are external to		from the process of assignment of trips to network
	the transportation system itself, such as tailpipe or evapo-		links. Where use of transit currently is anticipated to
	rative emission standards, limits on gasoline volatility,		be a significant factor in satisfying transportation
	inspection and maintenance programs, and oxygenated or		demand, these times should also be used for model-
	reformulated gasoline or diesel fuel. A regulatory pro-		ing mode splits.
	gram may also be considered to be adopted if an opt-in to	e.	Free-flow speeds on network links shall be based on
	a federally enforced program has been approved by EPA,		empirical observations.
	if EPA has promulgated the program (if the control pro-	f.	Peak and off-peak travel demand and travel times
	gram is a federal responsibility, such as tailpipe stan-		shall be provided.
	dards), or if the CAA requires the program without need	g.	Trip distribution and mode choice shall be sensitive
	for individual state action and without any discretionary		to pricing, where pricing is a significant factor, if the
	authority for EPA to set its stringency, delay its effective		network model is capable of such determinations
	date, or not implement the program.		and the necessary information is available.
4.	Notwithstanding  subsection   (A)(3),  during  the   transi-	h.	The model shall utilize and document a logical cor-
	tional period, control measures or programs which are		respondence between the assumed scenario of land
	committed to in an implementation plan submission as		development and use and the future transportation
	described in R18-2-1418 through R18-2-1420, but which		system  for  which  emissions  are  being  estimated.
	has not received final EPA action in the form of a finding		Reliance on a formal land-use model is not specifi-
	of  incompleteness,  approval,  or  disapproval,  may   be		cally required but is encouraged.
	assumed for emission reduction credit for the purpose of	i.	A dependence of trip generation on the accessibility
	demonstrating  that  the  requirements   of  R18-2-1418		of destinations via the transportation system, includ-
	through R18-2-1420 are satisfied.		ing pricing, is strongly encouraged but not specifi-
5.	A regional emissions analysis for the purpose of satisfy-		cally required, unless the network model is capable
	ing the requirements of R18-2-1422 through R18-2-1424		of such determinations and the necessary informa-
	may account for the programs in subsection (A)(4), but		tion is available.
	the same assumptions about these programs shall be used	j.	A dependence of regional economic and population
	for both the Baseline and Action scenarios.		growth on the accessibility of destinations via the
6.	Ambient temperatures shall be consistent with those used		transportation system is strongly encouraged but not
	to establish the emissions budget in the applicable imple-		specifically required, unless the network model is
	mentation  plan.  Factors   other  than  temperatures,  for		capable of such determinations and the necessary
	example the fraction of travel in a hot stabilized engine		information is available.
	mode, may be modified after interagency consultation	k.	Consideration of emissions increases from construc-
	according to R18-2-1405 if the newer estimates incorpo-		tion-related congestion is not specifically required.

rate additional or more geographically specific informa- tion or represent a logically estimated trend in such factors beyond the period considered in the applicable implementation plan.

B.       For serious, severe, and extreme ozone nonattainment areas and serious carbon monoxide areas after January 1, 1995, esti- mates of regional transportation-related emissions used to sup- port conformity determinations shall be made according to procedures which meet the requirements in subsections (B)(1) through (5).

1.        A network-based transportation demand model or models relating travel demand and transportation system perfor- mance to land-use patterns, population demographics, employment, transportation infrastructure, and transpor- tation policies shall be used to estimate travel within the metropolitan planning area of the nonattainment area. Such a model shall possess all of the following attributes:

a.         The modeling methods and the functional relation- ships used in the model shall in all respects be in accordance with acceptable professional practice and reasonable for purposes of emission estimation.

b.        The network-based model shall be validated against ground counts for a base year that is not more than 10 years prior to the date of the conformity determi- nation. Land use, population, and other inputs shall be based on the best available information and appropriate to the validation base year.

c.         For peak-hour or peak-period traffic assignments, a capacity sensitive assignment methodology shall be used.

d.        Zone-to-zone travel times used to distribute trips between origin and destination pairs shall be in rea- sonable agreement with the travel times which result

2.        Highway Performance Monitoring System (HPMS) esti- mates of vehicle miles traveled shall be considered the primary measure of vehicle miles traveled within the por- tion of the nonattainment or maintenance area and for the functional classes of roadways included in HPMS, for urban areas which are sampled on a separate urban area basis. A factor or factors shall be developed to reconcile and calibrate the network-based model estimates of vehi- cle miles traveled in the base year of its validation to the HPMS estimates for the same period, and these factors shall be applied to model estimates  of future  vehicle miles traveled. In this factoring process, consideration will be given to differences in the facility coverage of the HPMS and the modeled network description. Departure from these procedures is permitted with the concurrence of USDOT and EPA.

3.        Reasonable methods shall be used to estimate nonattain- ment area vehicle travel on off-network roadways within the urban transportation planning area and on roadways outside the urban transportation planning area.

4.        Reasonable methods in accordance with good practice shall be used to estimate traffic speeds and delays in a manner that is sensitive to the estimated volume of travel on each roadway segment represented in the network model.

C.      For areas which are not serious, severe, or extreme ozone non- attainment areas or serious carbon monoxide areas, or before January 1, 1995:

1.        Procedures which satisfy some or all of the requirements of subsection (A) shall be used in all areas not subject to subsection (A) in which those procedures have been the previous practice of the MPO.

Department of Environmental Quality – Air Pollution Control

2.        Regional emissions may be estimated by methods which do not explicitly or comprehensively account for the influence of land use and transportation infrastructure on vehicle miles traveled and traffic speeds and congestion. Such methods shall account for VMT growth by extrapo- lating historical VMT or projecting future VMT by con- sidering growth in population and historical growth trends for vehicle miles travelled per person. These meth- ods shall also consider future economic activity, transit alternatives, and transportation system policies.

D.      This subsection applies to any nonattainment or maintenance area or any portion thereof which does not have a metropolitan transportation plan or TIP and whose projects are not part of the emissions analysis of any MPO’s metropolitan transporta- tion plan or TIP (because the nonattainment or maintenance area or portion thereof does not contain a metropolitan plan- ning area or portion of a metropolitan planning area and is not part of a Metropolitan Statistical Area or Consolidated Metro- politan Statistical Area which is or contains a nonattainment or maintenance area).

1.        Conformity demonstrations for projects in these areas may satisfy the requirements of R18-2-1420, R18-2- 1424, and R18-2-1427 with one regional emissions anal- ysis which includes all the regionally significant transpor- tation projects in the nonattainment or maintenance area or portion thereof.

2.        The requirements of R18-2-1420 shall be satisfied according to the procedures in R18-2-1420(C), with ref- erences to the “transportation plan” taken to mean the statewide transportation plan.

3.        The requirements of R18-2-1424 and R18-2-1427 which reference “transportation plan” or “TIP” shall be taken to mean those projects in the statewide transportation plan or statewide TIP which are in the nonattainment or main- tenance area or portion thereof.

4.        The requirement of R18-2-1429(A)(2) shall be satisfied if all of the following are met:

a.         The project is included in the regional emissions analysis which includes all regionally significant highway and transportation projects in the nonattain- ment or maintenance area or portion thereof and supports the most recent conformity determination made according to the requirements of R18-2-1420, R18-2-1424 or R18-2-1427 (as modified by subsec- tions (D)(2) and (D)(3)), as appropriate for the time period and pollutant.

b.        The project’s design concept and scope have not changed significantly from those which were included in the regional emissions analysis or in a manner which would significantly impact use of the facility.

E.       For areas in which the implementation plan does not identify construction-related fugitive PM10 as a contributor to the non- attainment problem, the fugitive PM10  emissions associated with highway and transit project construction are not required to be considered in the regional emissions analysis.

F.       In PM10 nonattainment and maintenance areas with imple- mentation plans which identify construction-related fugitive PM10  as  a  contributor  to  the  nonattainment   problem,  the

regional PM10 emissions analysis shall consider construction- related fugitive PM10 and shall account for the level of con- struction activity, the fugitive PM10 control measures in the applicable   implementation   plan,   and   the   dust-producing

capacity of the proposed activities.

Historical Note

Adopted effective June 15, 1995 (Supp. 95-2).