N.M. Admin. Code § 20.2.99.142

Current through Register Vol. 35, No. 21, November 5, 2024

Section 20.2.99.142 - PROCEDURES FOR DETERMINING REGIONAL TRANSPORTATION-RELATED POLLUTANT EMISSIONS - ANALYSIS IN SERIOUS, SEVERE, AND EXTREME OZONE NONATTAINMENT AREAS AND SERIOUS CARBON MONOXIDE AREAS

Regional emissions analyses must meet the requirements of subsections A through C of 20.2.99.142 NMAC if their metropolitan planning area contains an urbanized area population over two hundred thousand (200,000).

A. By January 1, 1997, estimates of regional transportation-related emissions used to support conformity determinations must be made at a minimum using network-based travel models according to procedures and methods that are available and in practice and supported by current and available documentation. These procedures, methods, and practices are available from US DOT and will be updated periodically. Agencies must discuss these modeling procedures and practices through the interagency consultation process, as required by 20.2.99.120 NMAC. Network-based travel models must at a minimum satisfy the following requirements:

(1) Network-based models must be validated against observed counts (peak and off-peak, if possible) for a base year that is not more than ten (10) years prior to the date of the conformity determination. Model forecasts must be analyzed for reasonableness and compared to historical trends and other factors, and the results must be documented;

(2) Land use, population, employment, and other network-based travel model assumptions must be documented and based on the best available information;

(3) Scenarios of land development and use must be consistent with the future transportation system alternatives for which emissions are being estimated. The distribution of employment and residences for different transportation options must be reasonable;

(4) A capacity-sensitive assignment methodology must be used, and emissions estimates must be based on a methodology which differentiates between peak and off-peak link volumes and speeds and uses speeds based on final assigned volumes;

(5) Zone-to-zone travel impedances used to distribute trips between origin and destination pairs shall be in reasonable agreement with the travel times that are estimated from final assigned traffic volumes. Where use of transit currently is anticipated to be a significant factor in satisfying transportation demand, these times should also be used for modeling mode splits; and

(6) Network-based travel models must be reasonably sensitive to changes in the time(s), cost(s), and other factors affecting travel choices.

B. Reasonable methods in accordance with good practice must 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-based travel model.

C. Highway Performance Monitoring System (HPMS) estimates of vehicle miles traveled (VMT) shall be considered the primary measure of VMT within the portion 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. For areas with network-based travel models, a factor (or factors) may be developed to reconcile and calibrate the network-based model estimates of VMT in the base year of its validation to the HPMS estimates for the same period. These factors may then be applied to model estimates of future VMT. In this factoring process, consideration will be given to differences between HPMS and network-based travel models, such as differences in the facility coverage of the HPMS and the modeled network description. Locally developed count based programs and other departures from these procedures are permitted subject to the interagency consultation procedures of 20.2.99.120 NMAC.

N.M. Admin. Code § 20.2.99.142

12/14/94; 11/23/98; 20.2.99.142 NMAC - Rn, 20 NMAC 2.99.142 10/31/02