Document ID: EPA-R04-OAR-2014-0250-0180
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2016-02-16T05:00Z

Methodology Used to Develop MOVES Inputs

MOVES inputs were developed in accordance with guidance provided in EPA document 420b12028, titled "Using MOVES to prepare EIs for SIP and Conformity". Discussions on these inputs are presented below.

Meteorology data used for this analysis was based on local information obtained from NOAA data at the Memphis International Airport (MIA) and was adapted for MOVES using the EPA conversion tool.

Temperature  -  The minimum and maximum daily temperature estimates of 73F and 97F, respectively, were derived from temperatures recorded over a three year period on the ten highest ozone exceedance days. These values have been relied upon in previous state implementation plans and were determined to be appropriate for use in the ozone season through the interagency consultation group (IAC) process.

Reid Vapor Pressure (RVP)  -  7.8 pounds per square inch (psi) was used  as 40 CFR 80.270, titled "Controls and Prohibitions on Gasoline Volatility", indicates it is the ozone season regulatory maximum RVP  for Shelby County, Tennessee. This value has been relied upon in previous state implementation plans and was determined to be appropriate for use in ozone season through the interagency consultation group (IAC) process.

Humidity  -  In a pre-analysis consensus IAC discussion and as recorded in a May 17, 2013 memorandum (the document is located in Attachment II  -  Intergovernmental Consultation) of the plan revision), TDEC provided three-year average data from the MIA for the month of July, including hourly temperatures and relative humidity (see the table below). The consensus assumed the meteorological MIA data could be applied throughout the entire modeled area of Shelby County. Later, it was requested by the Department that the MPO use meteorological data (to include absolute humidity) in the 2014-2017 TIP and 2040 LRTP Conformity Demonstration, that had been used in the 2010 Shelby County Maintenance Plan for Ozone. However, the data introduced in the pre-analysis consensus was used to demonstrate conformity, which was acceptable, as the data was locally generated and therefore more representative than the MOVES default data.

                Hourly Temperature and Relative Humidity Values
                                    monthID
                                    hourID
                                  temperature
                                  relHumidity
                                    hourID
                                  temperature
                                  relHumidity
                                       7
                                       1
                                     78.2
                                     78.1
                                      13
                                     94.1
                                     56.0
                                       7
                                       2
                                     76.8
                                     79.9
                                      14
                                     96.1
                                     54.1
                                       7
                                       3
                                     75.7
                                     81.8
                                      15
                                     96.8
                                     52.7
                                       7
                                       4
                                     74.9
                                     82.9
                                      16
                                     97.0
                                     52.5
                                       7
                                       5
                                     74.3
                                     84.3
                                      17
                                     96.5
                                     52.8
                                       7
                                       6
                                     73.6
                                     85.4
                                      18
                                     95.1
                                     54.1
                                       7
                                       7
                                     73.0
                                     84.9
                                      19
                                     92.7
                                     57.2
                                       7
                                       8
                                     73.5
                                     79.7
                                      20
                                     89.6
                                     62.3
                                       7
                                       9
                                     76.5
                                     73.3
                                      21
                                     86.5
                                     67.3
                                       7
                                      10
                                     81.3
                                     67.7
                                      22
                                     83.8
                                     71.1
                                       7
                                      11
                                     86.2
                                     62.7
                                      23
                                     81.9
                                     74.4
                                       7
                                      12
                                     90.4
                                     59.1
                                      24
                                     80.0
                                     76.4

Source Type Population: MOVES default was used as a starting point for all source types. The MOVES Technical Guidance offers guidance on how to leverage default population and VMT data alongside local VMT data to arrive at an estimate of the local population. This guidance suggests comparing the ratio of default source type population to default VMT to the local VMT to arrive at an estimate of local source type population. This methodology was applied for all analysis years. A growth rate was not applied, since growth is inherently built in through this methodology.

 Age Distribution: Used Shelby County, TN-specific data obtained from the UTK paper "Tennessee Traffic Data for Estimating Air Pollution Emissions in 2002"  and an EPA converter to change MOBILE6-formatted information to MOVES format.

Vehicle Type VMT and VMT Fractions: This data importer asks the user for the VMT in the study area by HPMS vehicle class type, hourly VMT distributions, daily VMT distributions, and monthly VMT distributions. The HPMS vehicle class VMT is asked for on an annual basis. To determine this information, data was pulled from available travel demand models or from regional HPMS data.

HPMS Vehicle Class VMT  -  The HPMS vehicle class VMT was determined using the pre-processor developed within the travel demand model. The travel demand model classifies vehicles into automobiles, single unit trucks, and combination unit trucks. The three vehicle classes in the model were divided into the six HPMS vehicle class types through the pre-processor. Since the travel demand model produces daily weekday volumes, the EPA conversion tool was used to convert these daily VMT numbers to annual values.

Daily VMT Fraction  -  The University of Tennessee developed county-specific daily VMT fractions, which were applied in this analysis. This information was provided in a format appropriate for use in MOVES.

Monthly VMT Fraction  -  The University of Tennessee developed county-specific monthly VMT fractions, which were applied in this analysis. This information was provided in a format appropriate for use in MOVES.

Hourly VMT Fraction  -  The hourly VMT fraction was determined using the pre-processor developed within the travel demand model. To produce the information needed for the MOVES input file, the three vehicle classes in the model were expanded to the 13 MOVES vehicle source types. In addition, the four time of day periods in the model were expanded to represent each hour of the day. The default mix of off-network hourly distribution percentages was used for all vehicle classes.

The following table displays the Shelby County annual VMT produced by the MOVES VMT converter by source type and by year.

              Shelby County Annual VMT by Source Type and by Year
                                  Source Type
                                Source Type ID
                                Source Type VMT
                                       
                                       
                                     2006
                                     2021
Motorcycle
                                      11
                                                                     25,604,577
                                                                     30,597,047
Passenger Car
                                      21
                                                                  6,116,293,396
                                                                  7,308,869,710
Passenger Truck
                                      31
                                                                  1,393,265,928
                                                                  1,664,929,980
Light Commercial Truck
                                      32
                                                                    465,466,353
                                                                    556,224,433
Intercity Bus
                                      41
                                                                      3,712,127
                                                                      4,873,218
Transit Bus
                                      42
                                                                      1,942,992
                                                                      2,309,079
School Bus
                                      43
                                                                     25,201,662
                                                                     32,497,370
Refuse Truck
                                      51
                                                                      2,897,462
                                                                      2,074,341
Single Unit Shorthaul Truck
                                      52
                                                                    198,308,587
                                                                    249,731,833
Single Unit Longhaul Truck
                                      53
                                                                     25,487,609
                                                                     39,169,765
Motor Home
                                      54
                                                                     45,859,407
                                                                     59,508,279
Combination Short-haul Truck
                                      61
                                                                    166,694,865
                                                                    222,336,742
Combination Long-haul Truck
                                      62
                                                                    199,421,654
                                                                    316,912,033
Total
                                       
                                                                  8,670,156,620
                                                                 10,490,033,832

Average Speed Distribution: The average speed distribution was determined using the pre-processor developed within the travel demand model. The vehicle classes in the model were expanded to the 13 MOVES vehicle source types, and the hourly distribution was expanded from the four time periods in the model to each hour of the day.

Road Type Distribution: The road type distribution was determined using the pre-processor developed within the travel demand model. The vehicle classes in the model were expanded to the 13 MOVES vehicle source types

Ramp Fraction: The ramp fractions were determined using the pre-processor developed within the travel demand model.

Fuel Supply and Fuel Formulation: MOVES default data for Shelby County (obtained from the MOVES program) was used for analysis year 2006. The Tennessee Department of Environment and Conservation developed fuel supply and fuel formulation data for Shelby County for all analysis years 2012 and newer.

Fueltype and Technologies/Alternative Fuel Vehicle Types: If no information is entered for AVFT, MOVES assumes a default mix of alternative fuels. The MOVES default mix assumes a small percentage of compressed natural gas (CNG) transit buses. Since there are no CNG buses in the transit fleet for Shelby County, the default value for this file was modified to reflect only diesel and gasoline fuel types.

Inspection and Maintenance (I/M) Programs: The compliance factors in these files were adjusted to reflect not only participation within the City of Memphis, but also Shelby County as a whole. As stated in the EPA MOVES Technical guidance, this methodology can be used to avoid conducting two sets of runs that are then interpolated outside of MOVES.