March 17, 2006 

Appendix F - Activity Tech Memo.doc F-1

Appendix F 

Draft EMFAC Modeling Change Technical Memo 

SUBJECT: UPDATING ESTIMATES OF VEHICLE MILES TRAVELED 

AND SPEED DISTRIBUTIONS 

LEAD: PAM BURMICH and AGNES DUGYON 

SUMMARY

From November 2004 through May 2005, transportation planning agencies (TPAs) submitted 

motor vehicle activity data to the Air Resources Board (ARB) to be used in the 2005 update to 

the draft working version EMFAC2007 model. The TPAs represented the major urban areas of 

California. The activity data included vehicle miles traveled (VMT) and the distribution of VMT 

by speed and, in some cases, by time period. Statewide, the VMT update caused a 3% 

decrease in ROG emissions and a 6% decrease in NOx emissions in 2002 relative to VMT 

calculated with vehicle registration and smog check data. The update to speeds caused a 2% 

decrease in ROG emissions and a 1% decrease in NOx. This memorandum summarizes the 

TPA data submitted, the quality assurance data review process, and emissions impacts of 

VMT and speeds updates to the motor vehicle emissions inventory in more detail. 

DATA REVIEW

 

ARB reviewed the TPA data for anomalies and compared VMT and speed trends to past 

submittals and to other independent sources of data. Staff prepared individual assessments 

for each area of the state that submitted data. These assessments describe in detail the data 

submitted, major issues identified during the quality assurance process, and how these issues 

were resolved. The assessments included quality assurance questions presented to the TPAs 

and the answers provided by the TPAs. Also, ARB provided supporting files with VMT and 

speeds trend charts and data files formatted for the EMFAC model. 

 

ARB posted the assessments to ARB’s website and sent letters to the TPAs requesting their 

final review of the information. ARB revised the data as appropriate following TPA input. The 

updated assessments are listed here and are available with supporting documents at 

www.arb.ca.gov/planning/sip/emfacact05/emfacact05.htm. 

#520 Southern California Association of Governments (SCAG) 

#526 Metropolitan Transportation Commission (MTC) 

#546 Sacramento Area Council of Governments (SACOG)

#556 San Diego Association of Governments (SANDAG) 

#557 Santa Barbara County Association of Governments (SBCAG) 

#558 San Joaquin Valley Transportation Planning Agencies (SJV TPAs) 

#559 Association of Monterey Bay Area Governments (AMBAG) 

#575 Butte County Association of Governments (BCAG) and Tahoe Regional Planning Agency (TRPA) 

When the quality assurance process was completed, ARB processed the data into a format 

compatible with the EMFAC model. 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-2

DATA SUBMITTED

In general, the TPAs provided VMT estimates for the total vehicles in the fleet. There were 

instances where TPAs provided VMT data in more detail by vehicle type; however, after 

consultations with the TPAs, ARB used updated DMV data to distribute total VMT to the 13 

vehicle classes. In particular, heavy-duty VMT was assigned according to ARB’s recent 

heavy-duty vehicle statewide VMT redistribution. 

The TPAs provided speed distributions for light-duty vehicles, medium-duty vehicles, and 

motorcycles. In some cases, they provided speeds for heavy-duty vehicles as well. After 

consultation, ARB updated the light- and medium-duty fleet using the TPA speed distributions, 

but left heavy-duty speeds unchanged in the model. The heavy-duty speeds were not 

changed largely because the heavy-duty statewide VMT redistribution occurred after the travel 

demand model speeds had been developed. Since in most cases the heavy-duty speeds 

currently in the EMFAC model reflect instrumented vehicle studies, it was thought better to 

leave the speeds unchanged for now. There will be opportunity to revisit heavy-duty speeds in 

CY 2006. 

In the coming year, the TPAs will be improving their travel demand models and updating 

special truck and transit models. In addition, ARB has agreed to work with TPAs to resolve 

discrepancies between ARB VMT estimates and travel demand model VMT estimates. The 

area-specific assessments discuss all of these issues in more detail. 

VMT Updates 

Table 1 summarizes the calendar years (CYs) of VMT data received from the TPAs. Only one 

base year among CYs 2000, 2001, 2002, and 2003 could be used to populate the EMFAC 

model. Some areas provided data for more than one base year. The ones selected for the 

model are shown in Table 1. 

CY 2040 appears for all areas. If an area did not provide 2040 data, ARB extrapolated VMT 

data to 2040 by compounding the TPA growth rates provided for the nearest prior time period. 

SACOG (and MTC for Solano County) provided data for CY 2000; however, due to the VMT 

adjustments agreed upon by SACOG, the Sacramento Metropolitan Air Quality Management 

District, and ARB, CY 2003 was selected for the base year. (See Assessment # 546 for 

details.) 

The VMT provided by the TPAs was entered into the EMFAC model using a VMT matching 

algorithm. The Appendix to this memorandum describes how the VMT matching algorithm 

operates to match TPA VMT data in the EMFAC model.
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-3

Table 1: VMT Data Provided by Area 

AGENCY COUNTY AIR BASIN AREA BASE YEARS CALENDAR YEARS RECEIVED

AMBAG Monterey North Central Coast 16 2000 2010 2020 2030 2040 Nov 04

San Benito North Central Coast 17 2000 2010 2020 2030 2040

Santa Cruz North Central Coast 18 2000 2010 2020 2030 2040

BCAG Butte Sacramento Valley 27 2000 2010 2015 2020 2025 2040 2004

MTC Alameda San Francisco 39 2000 2006 2007 2015 2025 2030 2040 Dec 04 - May 05

Contra Costa San Francisco 40 2000 2006 2007 2015 2025 2030 2040

Marin San Francisco 41 2000 2006 2007 2015 2025 2030 2040

Napa San Francisco 42 2000 2006 2007 2015 2025 2030 2040

San Francisco San Francisco 43 2000 2006 2007 2015 2025 2030 2040

San Mateo San Francisco 44 2000 2006 2007 2015 2025 2030 2040

Santa Clara San Francisco 45 2000 2006 2007 2015 2025 2030 2040

So. Solano (SF) San Francisco 46 2000 2007 2015 2025 2030 2040

So. Sonoma (SF) San Francisco 47 2000 2007 2015 2025 2030 2040

No. Sonoma (NC) North Coast 22 2000 2007 2015 2025 2030 2040

SACOG ElDorado (MC) Sacramento 9 2003 2005 2008 2013 2020 2027 2040 Dec 04 - Mar 05

Placer (SV) Sacramento 30 2003 2005 2008 2013 2020 2027 2040

Placer (MC) Sacramento 12 2003 2005 2008 2013 2020 2027 2040

Sacramento Sacramento 31 2003 2005 2008 2013 2020 2027 2040

Sutter Sacramento 34 2003 2005 2008 2013 2020 2027 2040

Yolo Sacramento 36 2003 2005 2008 2013 2020 2027 2040

Yuba Sacramento 37 2003 2005 2008 2013 2020 2027 2040

MTC Solano (SV) Sacramento 33 2003 2007 2015 2025 2030 2040

SANDAG San Diego San Diego 38 2002 2008 2009 2010 2014 2020 2030 2040 Dec 04 - Mar 05

FRESNO COG Fresno San Joaquin Valley 48 2000 2005 2008 2010 2020 2030 2040 Feb 05 - Mar 05

KERN COG Kern (SJV) San Joaquin Valley 49 2000 2005 2008 2010 2015 2020 2030 2040

KINGS CAG Kings San Joaquin Valley 50 2000 2005 2008 2010 2020 2030 2040

MADERA CTC Madera San Joaquin Valley 51 2000 2005 2008 2010 2020 2030 2040

MERCED CAG Merced San Joaquin Valley 52 2000 2005 2008 2010 2020 2030 2040

SJCOG San Joaquin San Joaquin Valley 53 2000 2005 2008 2010 2020 2030 2040

STANISLAUS COG Stanislaus San Joaquin Valley 54 2000 2005 2008 2010 2020 2030 2040

TULARE CAG Tulare San Joaquin Valley 55 2003 2005 2008 2010 2020 2030 2040

KERN COG Kern (MD) Mojave Desert 65 2000 2005 2008 2010 2015 2020 2030 2040

SBCAG Santa Barbara South Central Coast 57 2000 2005 2010 2015 2020 2030 2040 Feb 05

SCAG Los Angeles South Coast 59 2000 2005 2010 2015 2020 2025 2030 2040 Jan 05 - Apr 05

SCAG Orange South Coast 60 2000 2005 2010 2015 2020 2025 2030 2040

SCAG Riverside with Banning South Coast 61 2000 2005 2010 2015 2020 2025 2030 2040

SCAG San Bernardino South Coast 62 2000 2005 2010 2015 2020 2025 2030 2040

SCAG Los Angeles (Antelope Valley) Mojave Desert 68 2000 2005 2010 2015 2020 2025 2030 2040

SCAG San Bernardino (VV + MV) Mojave Desert 69 2000 2005 2010 2015 2020 2025 2030 2040

SCAG Riverside (Coachella Valley) Salton Sea 64 2000 2005 2010 2015 2020 2025 2030 2040

SCAG Ventura South Central Coast 58 2000 2005 2010 2015 2020 2025 2030 2040

Speed Updates 

The TPAs provided speeds for the light-duty fleet (PC, LDT1, LDT2, T3, and MCYs). Typically, 

ARB default speed distributions based on instrumented vehicle studies are used for heavyduty vehicles. 

Table 2 summarizes the CYs of speed distributions provided by the TPAs. ARB did not 

interpolate or extrapolate speed distributions, but applied the speed distribution for the next 

future year to interim years. For example, if speeds were provided for CYs 2000, 2005, and 

2020, then the 2005 speeds were applied to CYs 2001 through 2005. Likewise, 2020 speeds 

were applied to CYs 2006 through 2020. In this example, since no speeds were provided for 

out-years, the 2020 speeds would be applied through 2040. 

Santa Barbara was the only exception to the typical approach. SBCAG provided specific 

instructions as to what speeds would be applied to specific CYs. (See Assessment #557 for 

details.) 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-4

Table 2: Speeds Data Provided by Area 

AGENCY COUNTY AIR BASIN AREA CALENDAR YEARS RECEIVED

AMBAG Monterey North Central Coast 16 2010 2020 2025 2030 Nov 04

San Benito North Central Coast 17 2010 2020 2025 2030

Santa Cruz North Central Coast 18 2010 2020 2025 2030

BCAG Butte Sacramento Valley 27 2000 2010 2015 2020 2025 2004

MTC Alameda San Francisco 39 2000 2006 2007 2015 2025 2030 Dec 04 - May 05

Contra Costa San Francisco 40 2000 2006 2007 2015 2025 2030

Marin San Francisco 41 2000 2006 2007 2015 2025 2030

Napa San Francisco 42 2000 2006 2007 2015 2025 2030

San Francisco San Francisco 43 2000 2006 2007 2015 2025 2030

San Mateo San Francisco 44 2000 2006 2007 2015 2025 2030

Santa Clara San Francisco 45 2000 2006 2007 2015 2025 2030

So. Solano (SF) San Francisco 46 2000 2007 2015 2025 2030

So. Sonoma (SF) San Francisco 47 2000 2007 2015 2025 2030

No. Sonoma (NC) North Coast 22 2000 2007 2015 2025 2030

SACOG ElDorado (MC) Sacramento 9 2000 2005 2008 2013 2020 2027 Dec 04 - Mar 05

Placer (SV) Sacramento 30 2000 2005 2008 2013 2020 2027

Placer (MC) Sacramento 12 2000 2005 2008 2013 2020 2027

Sacramento Sacramento 31 2000 2005 2008 2013 2020 2027

Sutter Sacramento 34 2000 2005 2008 2013 2020 2027

Yolo Sacramento 36 2000 2005 2008 2013 2020 2027

Yuba Sacramento 37 2000 2005 2008 2013 2020 2027

MTC Solano (SV) Sacramento 33 2000 2007 2015 2025 2030

SANDAG San Diego San Diego 38 2002 2008 2009 2010 2014 2020 2030 Dec 04 - Mar 05

FRESNO COG Fresno San Joaquin Valley 48 2000 2002 2005 2008 2010 2020 2030 Feb 05 - Mar 05

KERN COG Kern (SJV) San Joaquin Valley 49 2000 2005 2008 2010 2015 2020 2030

KINGS CAG Kings San Joaquin Valley 50 2000 2002 2005 2008 2010 2020 2030

MADERA CTC Madera San Joaquin Valley 51 2000 2005 2008 2010 2020 2030

MERCED CAG Merced San Joaquin Valley 52 2000 2002 2005 2008 2010 2020 2030

SJCOG San Joaquin San Joaquin Valley 53 2000 2005 2008 2010 2020 2030

STANISLAUS COG Stanislaus San Joaquin Valley 54 2000 2005 2008 2010 2020 2030

TULARE CAG Tulare San Joaquin Valley 55 2003 2005 2008 2010 2020 2030

KERN COG Kern (MD) Mojave Desert 65 2000 2005 2008 2010 2015 2020 2030

SBCAG Santa Barbara South Central Coast 57 2000 2005 2010 2015 2020 2030 Feb 05

SCAG Los Angeles South Coast 59 2000 2002 2005 2010 2015 2020 2025 2030 2040 Jan 05 - Apr 05

Orange South Coast 60 2000 2002 2005 2010 2015 2020 2025 2030 2040

Riverside with Banning South Coast 61 2000 2002 2005 2010 2015 2020 2025 2030 2040

San Bernardino South Coast 62 2000 2002 2005 2010 2015 2020 2025 2030 2040

Los Angeles (Antelope Valley) Mojave Desert 68 2000 2002 2005 2010 2015 2020 2025 2030 2040

San Bernardino (VV + MV) Mojave Desert 69 2000 2002 2005 2010 2015 2020 2025 2030 2040

Riverside (Coachella Valley) Salton Sea 64 2000 2002 2005 2010 2015 2020 2025 2030 2040

Ventura South Central Coast 58 2000 2002 2005 2010 2015 2020 2025 2030 2040

TRPA El Dorado (LT) Lake Tahoe 5 2003 2010 2018 (all years have the same speed distribution) 2004

Placer (LT) Lake Tahoe 6 2003 2010 2018 (all years have the same speed distribution) 2004

Time Period Definition Updates 

 

Part of the speed submittals is the period definitions. The period definitions are the time-of-day 

periods associated with each speed distribution provided by the TPAs. Table 3 summarizes 

the period definitions by area. 

Period definitions are typically the same for a given area for all forecasted years in the EMFAC 

model. For the first time, Santa Barbara provided period definitions that change over time to 

show a spreading of peak travel due to increases in traffic congestion. In the future, ARB 

expects that other areas will begin to show peak spreading by varying period definitions over 

time. 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-5

Table 3: Time Period Definitions for EMFAC 2007

TPA Air Basin/ Period 1 Period 2 Period 3 Period 4 Period 5 Period 6

Area County SPEED DISTRIBTUTIONS District Off Peak AM Peak Mid Day Mid Day PM Peak Off Peak

BCAG DAILY

27 Butte SV/BUT

AMBAG AMPK, PMPK, OFFPK

16 Monterey NCC/MBU Hours 0-5 6,7,8 9,10,11 12,13,14 15, 16, 17 18-23

17 San Benito NCC/MBU " " " " " "

18 Santa Cruz NCC/MBU " " " " " "

MTC PK (Per. 2, 5), OFFPK (Per. 1,3,4,6)

39 Alameda SF/BA Hours 0-5 6,7,8 9,10,11 12,13,14 15, 16, 17 18-23

40 Contra Costa SF/BA " " " " " "

41 Marin SF/BA " " " " " "

42 Napa SF/BA " " " " " "

43 San Francisco SF/BA " " " " " "

44 San Mateo SF/BA " " " " " "

45 Santa Clara SF/BA " " " " " "

46 Solano (SF) SF/BA " " " " " "

33 Solano (SV) SV/YS " " " " " "

47 Sonoma (SF) SF/BA " " " " " "

22 Sonoma (NC) NC/NS " " " " " "

SACOG AM, MID, PM, EVENING 

9 El Dorado (MC) MC/ED Hours 0-5 6,7,8 9,10,11 12,13,14 15, 16, 17 18-23

30 Placer (SV) SV/PLA " " " " " "

12 Placer (MC) MC/PLA " " " " " "

31 Sacramento SV/SAC " " " " " "

34 Sutter SV/FR " " " " " "

36 Yolo SV/YS " " " " " "

37 Yuba SV/FR " " " " " "

SANDAG PERIODS 1 - 6

38 San Diego SD/SD Hours 0-5 6,7,8 9,10,11 12,13,14 15, 16, 17 18-23

SCAG AMPK, PMPK, MIDDAY, NIGHT

59 Los Angeles SC/SC Hours 0-5 6,7,8 9,10,11 12,13,14 15,16,17,18 19-23

68 Los Angeles (Antelope Valley) MD/AV " " " " " "

60 Orange SC/SC " " " " " "

61 Riverside (Banning) SC/SC " " " " " "

64 Riverside (Coachella Valley) SS/SC " " " " " "

67 Riverside MD/SC " " " " " "

66 Riverside MD/MOJ " " " " " "

62 San Bernardino SC/SC " " " " " "

69 San Bernardino (Victor Valley and Mojave Valley) MD/MOJ " " " " " "

58 Ventura SCC/VEN " " " " " "

SJV TPAs

48 Fresno AMPK, PMPK, OFFPK SJV/SJU Hours 0-5 6,7,8 9,10,11 12,13,14 15, 16, 17 18-23

49 Kern AM, PM, MD, OFF SJV/SJVU Hours 0-6 7,8 9,10,11 12,13,14 15, 16, 17 18-23

65 Kern AM, PM, MD, OFF MD/KER Hours 0-6 7,8 9,10,11 12,13,14 15, 16, 17 18-23

50 Kings DAILY SJV/SJU

51 Madera DAILY SJV/SJU

52 Merced DAILY SJV/SJU

53 San Joaquin DAILY SJV/SJU

54 Stanislaus DAILY SJV/SJU

55 Tulare AM, PM, OFF SJV/SJU Hours 0-5 6,7,8 9,10,11 12,13,14 15, 16, 17 18-23

TRPA (Lake Tahoe) DAILY 

5 El Dorado LT/ED

6 Placer LT/PLA

SBCAG AMPK, PMPK, OFFPK

57 Santa Barbara VARIES BY YEAR SCC

CY 2000 Hours 0-6 7-8 9-11 12-15 16,17 18-23

CY 2005 Hours 0-6 7-8 9-11 12-15 16,17 18-23

CY 2010 Hours 0-5 6-8 9-11 12-14 15-17 18-23

CY 2015 Hours 0-5 6-9 10-11 12-14 15-18 19-23

CY 2020 Hours 0-5 6-9 10-11 12-14 15-18 19-23

CY 2030 Hours 0-5 6-9 10-11 12-14 15-18 19-23

 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-6

Activity Data Issues

During the QA process, ARB staff raised questions with each of the TPAs regarding the activity 

data submittals. Details on the VMT and speeds issues are provided in the assessments for 

each area; however, there were two issues of particular interest—the slowing of growth rates 

compared to previous submittals and baseline VMT estimates that were noticeably less than 

other sources of data. 

Slower VMT growth was reported by SCAG, MTC, SAGOG, and AMBAG. The TPAs offered 

their updated socioeconomic (i.e., population and job growth) estimates as the reason for the 

slower VMT growth rates. 

The VMT baselines submitted for SCAG, MTC, SACOG, and the San Joaquin Valley region 

were less than both MVSTAFF and DMV/Smog Check estimates. In the case of MTC and 

SACOG, the discrepancies were significant enough that ARB made adjustments to the TPA 

VMT baselines, as was noted earlier in this document, before entering the data into the 2005 

update of the EMFAC model. These adjustments are considered temporary and were the 

result of agreements reached with the TPAs and air districts. ARB and the TPAs do not know 

the reasons for the discrepancies and have agreed to pursue answers over the coming 

months. 

The following charts were taken from the assessments developed during the QA process. 

They compare the VMT trends and growth rates from several sources of data. The data 

sources typically included: 

TPA VMT forecasts as submitted to ARB from November 2004 to March 2005 

(Local VMT) 

TPA VMT forecasts previously submitted to ARB usually represented in EMFAC2002, 

Version 2.2 (EMFAC2002, V2.2 (Apr03))

The most recently adopted State Implementation Plan for the area (SIP VMT)

Caltrans VMT forecasts from the California Motor Vehicle Stock, Travel and Fuel 

Forecast, Nov 2003 (MVSTAFF VMT)

Human population trends taken from the State of California, Department of Finance, 

Demographic Research Unit, “Population Projections by Race/Ethnicity for California 

and Its Counties 2000-2050, Sacramento, California, May 2004. (Human Population) 

If a data source was missing an interim year, ARB straight-line interpolated to complete the 

VMT trend. The comparisons were based on whole county VMT estimates and are not 

necessarily limited to air basin boundaries. The county level comparisons along with 

questions/issues raised during the QA process are available at the website: 

____________________ . 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-7

San Francisco Bay Area

Vehicle Miles Traveled

 and Human Population

0

50,000

100,000

150,000

200,000

250,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

9,000,000

Population

Local VMT SIP 2004 VMT

MVStaff VMT (Adj) Human Population (Adj)

Growth Rates

1.00

1.30

1.60

2000 2005 2010 2015 2020 2025 2030

(Adjusted) 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-8

Monterey Bay Area

Growth Rates

1.00

1.25

1.50

1.75

2.00

2.25

2000 2005 2010 2015 2020 2025 2030

Vehicle Miles Traveled

 and Human Population

0

10,000

20,000

30,000

40,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

900,000

1,000,000

Population

Local VMT EMFAC2002 V2.2 (Apr03)

MVStaff VMT Human Population
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-9

Sacramento Planning Area

Vehicle M iles Traveled

 and Human Population

0

10,000

20,000

30,000

40,000

50,000

60,000

70,000

80,000

90,000

100,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

Population

Local VMT EMFAC2002 V2.2 (Apr03)

MVStaff VMT Human Population

Growth Rates

1.00

1.25

1.50

1.75

2.00

2000 2005 2010 2015 2020 2025 2030

(Unadjusted) 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-10

San Diego County

Vehicle M iles Traveled

 and Human Population

0

25,000

50,000

75,000

100,000

125,000

150,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

500,000

1,000,000

1,500,000

2,000,000

2,500,000

3,000,000

3,500,000

4,000,000

4,500,000

Population

Local VMT EMFAC2002 V2.2 (Apr03) VMT

MVStaff VMT Human Population

Growth Rates

1.00

1.25

1.50

1.75

2.00

2000 2005 2010 2015 2020 2025 2030
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-11

San Joaquin Valley

Vehicle M iles Traveled

 and Human Population

0

50,000

100,000

150,000

200,000

250,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

Local VMT Extreme Ozone SIP

EMFAC2002 V2.2 (Apr03) MV Staff

Human Population

Growth Rates

1.00

1.50

2.00

2.50

2000 2005 2010 2015 2020 2025 2030
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-12

Santa Barbara County

Vehicle M iles Traveled

 and Human Population

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

100,000

200,000

300,000

400,000

500,000

Population

Local VMT EMFAC2002 V2.2 (Apr03)

MVStaff VMT Human Population

Growth Rates

1.00

1.20

1.40

1.60

1.80

2.00

2000 2005 2010 2015 2020 2025 2030
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-13

South Coast Region

Vehicle M iles Traveled

 and Human Population

0

100,000

200,000

300,000

400,000

500,000

600,000

700,000

800,000

2000 2005 2010 2015 2020 2025 2030

VMT in 1,000's

0

2,000,000

4,000,000

6,000,000

8,000,000

10,000,000

12,000,000

14,000,000

16,000,000

18,000,000

20,000,000

22,000,000

Population

Local VMT SIP 2003 VMT

MVStaff VMT EMFAC2002 V2.2 (Apr03)

Human Population

Growth Rates

1.00

1.20

1.40

1.60

1.80

2000 2005 2010 2015 2020 2025 2030
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-14

Emission Impacts from New VMT (Relative to EMFAC 2002)

In order to compare emissions associated with the new Working Draft activity data to 

emissions associated with prior activity data, staff ran the new EMFAC, Version 2.22.8.51209 

model in two ways: (1) using activity defaults (the new activity data) and (2) using activity data 

from EMFAC2002, Version 2.2 (Apr03). 

Table A shows the difference when the summer season WIS enabled (prior activity) model 

runs are subtracted from the default (new activity) model runs. Negative numbers indicate that 

the new values are lower than the prior values. Thus, statewide, there was an increase in 

VMT and corresponding emissions resulting from the new data. In 2002, the increase was 70 

tons per day of ROG, 111 tons per day of NOx, and 5 tons per day of PM10. 

In the base year 2002, the San Joaquin Valley Air Basin shows a decrease in VMT and 

emissions. South Coast, San Joaquin Valley, and San Francisco Air Basins show less VMT 

and emissions for out years 2015 and 2020. In the South Coast, the new activity data 

decreased ROG by 10 tons per day, NOx by 14 tons per day, and PM10 by 1 ton per day in 

2015 with a slightly bigger decrease in 2020. 

Table B shows the percent change in emissions, vehicle population, and VMT. Emission 

changes range from 7 percent decrease to 6 percent increase depending on the calendar year 

and area. 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-15

Table A 

Changes in Emissions 

Draft EMFAC 2007 VMT Compared to E07 with E02 VMT

Tons/Day Vehicles Miles/Day

ROG CO NOx CO2 PM10 Pop VMT in 1,000's

CY2002

Statewide 70 625 111 32 5 1,716,700 53,521

South Coast Air Basin 24 204 31 11 1 618,600 18,310

San Joaquin Valley Air Basin -4 -33 -9 -2 0 -73,780 -2,477

San Diego Air Basin 2 21 3 1 0 61,150 2,036

San Francisco Air Basin 7 62 9 3 0 172,450 5,174

CY2015

Statewide 4 28 6 4 0 244,300 7,450

South Coast Air Basin -10 -68 -14 -11 -1 -655,600 -18,746

San Joaquin Valley Air Basin -4 -24 -8 -4 0 -183,830 -6,155

San Diego Air Basin 0 1 0 0 0 6,680 212

San Francisco Air Basin -1 -9 -2 -1 0 -89,050 -2,598

CY2020

Statewide 0 3 1 1 0 40,500 1,240

South Coast Air Basin -12 -73 -15 -18 -2 -1,049,300 -29,974

San Joaquin Valley Air Basin -2 -15 -5 -4 0 -180,570 -6,134

San Diego Air Basin 1 7 1 2 0 89,170 2,816

San Francisco Air Basin -1 -10 -2 -3 0 -147,960 -4,305

Source: EMFAC Working Draft, Version 2.22.8.51209, default compared to WIS enabled, summer.

Vehicle populations were adjusted in order to change VMT.
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-16

Table B 

Percent Change in Emissions 

Draft EMFAC 2007 VMT Compared to E07 with E02 VMT

Vehicle

ROG CO NOx CO2 PM10 Pop VMT

CY2002

Statewide 6% 6% 6% 6% 6% 6% 6%

South Coast Air Basin 6% 6% 6% 6% 6% 6% 6%

San Joaquin Valley Air Basin -3% -3% -3% -3% -3% -3% -3%

San Diego Air Basin 3% 3% 3% 3% 3% 3% 3%

San Francisco Air Basin 3% 3% 3% 3% 3% 3% 3%

CY2015

Statewide 1% 1% 1% 1% 1% 1% 1%

South Coast Air Basin -5% -5% -5% -5% -5% -5% -5%

San Joaquin Valley Air Basin -5% -5% -5% -5% -5% -5% -5%

San Diego Air Basin 0% 0% 0% 0% 0% 0% 0%

San Francisco Air Basin -1% -1% -1% -1% -1% -1% -1%

CY2020

Statewide 0% 0% 0% 0% 0% 0% 0%

South Coast Air Basin -7% -7% -7% -7% -7% -7% -7%

San Joaquin Valley Air Basin -5% -5% -5% -5% -5% -5% -5%

San Diego Air Basin 3% 3% 3% 3% 3% 3% 3%

San Francisco Air Basin -2% -2% -2% -2% -2% -2% -2%

Source: EMFAC Working Draft, Version 2.22.8.51209, default compared to WIS enabled, summer.

Vehicle populations were adjusted in order to change VMT.
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-17

Emissions Impacts from New VMT (Relative to ARB Calculated VMT)

Another way that ARB estimates the impacts associated with a given change in the EMFAC 

model is by making one type of change at a time and then comparing the difference in 

emissions. Version 2.225 of the EMFAC model reflects revisions made up to the point of 

changing VMT to reflect the TPA VMT submittals. Version 2.226 was updated to reflect the 

new TPA VMT submittal. Thus, the difference between 2.225 and 2.226 can be attributed to 

the difference in VMT methodologies. 

One point of clarification is that Version 2.225 includes updated DMV/BAR data used to 

establish base year vehicle populations, accrual rates, and resulting VMT. Also, heavy heavyduty diesel truck (HHDDT) growth rates were revised during ARB’s recent redistribution of 

statewide HHDDT VMT. Hence, the VMT assignments used as the base case in the following 

comparisons are different than those in EMFAC 2002, Version 2.2 which contains previous 

TPA data and will be used in air quality plans and evaluations up to the release of EMFAC 

2007.

Given that TPA VMT estimates were less than the VMT in EMFAC Version 2.225 calculated 

from DMV/BAR data, the emissions associated with the new VMT are also less. 

Table 4 shows the differences in emissions, vehicle population, and VMT between Version 

2.225 and 2.226. In CY 2002 there was roughly 8% fewer VMT resulting in 3% less ROG, 6% 

less NOx, and 7% less PM10 statewide. In CY 2020 there was roughly 16% fewer VMT, 6% 

less ROG, 7% less NOx, and 16% less PM10. 

Table 4 also shows that the South Coast had 14% less VMT causing 4% less ROG, 10% less 

NOx, and 12% less PM10 in CY 2002 when compared to EMFAC Version 2.225. In 2020, the 

South Coast had 27% less VMT resulting in 10% less ROG, 10% less NOx, and 27% less 

PM10. 

For more detailed information, see Tables 6 through 12 at the end of this memorandum. 

Table 4: Changes in Emissions from New VMT 

 EMFAC Version 2.226 Compared to 2.225 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-18

tons/day vehicles miles/day

ROG CO NOx CO2 PM10 POP VMT

Year 2002

Statewide -29.94 -881.31 -109.91 -39,900 -5.44 0 -79,719,430

South Coast Air Basin -18.34 -605.75 -60.68 -27,091 -2.93 0 -55,973,630

San Joaquin Valley Air Basin -3.64 -82.34 -18.40 -3,674 -1.06 0 -6,048,760

Sacramento Valley Air Basin -0.57 -13.06 -2.17 -454 -0.11 0 -785,352

San Diego Air Basin -0.45 -10.60 -1.67 -532 -0.08 0 -976,184

San Francisco Air Basin -7.34 -163.62 -27.25 -7,164 -1.16 0 -13,771,500

Year 2015

Statewide -33.96 -600.41 -61.22 -93,303 -9.23 -2,681,268 -178,640,000

South Coast Air Basin -20.95 -400.39 -27.39 -59,185 -5.76 -1,805,238 -119,369,190

San Joaquin Valley Air Basin -2.12 -44.03 -14.36 -9,608 -1.03 -147,136 -14,454,850

Sacramento Valley Air Basin -0.54 -8.22 -1.95 -914 -0.13 -15,385 -1,489,020

San Diego Air Basin -1.79 -17.53 -3.12 -2,907 -0.29 -123,930 -5,223,240

San Francisco Air Basin -6.16 -108.73 -16.53 -15,885 -1.77 -351,758 -27,441,740

Year 2020

Statewide -27.96 -454.64 -50.16 -109,511 -10.59 -3,396,152 -207,707,000

South Coast Air Basin -17.26 -300.62 -21.20 -68,318 -6.66 -2,278,627 -137,600,320

San Joaquin Valley Air Basin -1.89 -35.51 -12.10 -11,678 -1.09 -212,650 -17,355,760

Sacramento Valley Air Basin -0.26 -5.14 -1.20 -864 -0.11 -8,654 -1,402,300

San Diego Air Basin -1.31 -11.04 -1.74 -1,582 -0.20 -71,119 -2,773,400

San Francisco Air Basin -4.75 -78.94 -11.85 -19,356 -1.94 -479,906 -33,627,130

ROG includes total exhaust plus evaporative emissions.

PM10 includes total exhaust plus tire/brake wear emissions.

Emissions Impacts from New Speeds

Speed distributions are entered directly into the EMFAC model. To find the emissions impacts 

from the new TPA speeds, staff compared Version 2.226 to Version 2.227. Version 2.227 is 

identical to 2.226 except that the new TPA speeds were added to the model. 

The speeds in EMFAC Version 2.226 were carried forward from EMFAC 2002, Version 2.2. 

The change in emissions is the result of updating the light- and medium-duty vehicle fleet 

speed distributions with the new TPA speeds. Sometimes the new speeds were slower than 

past submittals showing the effects of congestion. Other times, the speeds were faster than 

past submittals, showing the impact from new transportation projects built or planned. The 

emission impacts varied by area, but statewide emissions increased as a result of the new 

speeds. 

Table 5 shows that statewide, the new TPA speeds caused a 2% increase in ROG emissions, 

less than 1% increase in NOx, and 1% increase in PM10 in CY 2002. CY 2020 showed an 

increase of less than 1% for ROG and NOx and roughly 1% increase in PM10 statewide. 

For the South Coast, new speeds caused a 3% increase in ROG, less than 1% increase in 

NOx, and 2% increase in PM10 in CY 2002. In CY 2020 there was less than 1% increase in 

ROG and NOx and roughly 3% increase in PM10. 

Tables 13 through 19 found at the end of this memorandum provide additional details on 

emission impacts from the new speeds by area. 

 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-19

Table 5: Changes in Emissions from New Speeds 

EMFAC Version 2.227 Compared to Version 2.226 

tons/day

ROG CO NOx CO2 PM10

Year 2002

Statewide 21.32 207.26 10.59 17,176 0.89

South Coast Air Basin 10.86 91.12 3.94 8,667 0.49

San Joaquin Valley Air Basin 0.99 11.46 0.22 681 0.01

Sacramento Valley Air Basin 0.69 10.07 0.84 656 0.02

San Diego Air Basin 0.52 5.36 0.32 462 0.03

San Francisco Bay Area 6.83 76.21 5.43 5,752 0.24

Year 2015

Statewide 2.66 14.55 4.18 7,658 0.64

South Coast Air Basin 1.23 13.91 1.31 5,877 0.39

San Joaquin Valley Air Basin 0.57 8.88 0.16 1,672 0.12

Sacramento Valley Air Basin 0.09 -0.34 0.17 385 0.00

San Diego Air Basin 0.28 4.02 0.14 914 0.09

San Francisco Bay Area -0.77 -15.56 0.01 -1,880 -0.23

Year 2020

Statewide 2.02 10.93 2.77 9,873 0.69

South Coast Air Basin 0.89 12.33 0.92 6,881 0.51

San Joaquin Valley Air Basin 0.35 5.51 0.11 1,569 0.11

Sacramento Valley Air Basin -0.01 -2.67 0.05 -17 -0.03

San Diego Air Basin 0.15 2.66 0.10 792 0.08

San Francisco Bay Area -0.24 -10.58 0.10 -600 -0.15

ROG includes total exhaust plus evaporative emissions.

PM10 includes total exhaust plus tire/brake wear emissions.

 

Table 6: Statewide New VMT and Emission Impacts 
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-20

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 14,817,640 497,419,840 3605.04 33282.71 2589.22 329154.60 73.55

1990 22,515,974 786,020,420 2546.91 26510.16 2792.00 477633.40 119.32

2000 26,785,744 897,559,680 1407.16 13580.21 2117.27 513539.40 84.29

2002 28,178,674 958,260,290 1155.76 10937.50 1927.04 545244.80 79.16

2005 30,910,260 1,034,734,700 1019.65 9097.96 1795.05 591358.10 81.38

2010 33,960,136 1,121,785,100 767.72 6507.64 1342.03 641240.60 72.04

2015 36,789,816 1,219,000,600 580.58 4510.23 937.79 709149.40 68.31

2020 39,667,496 1,318,458,400 454.89 3198.95 670.13 773355.50 67.53

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 14,820,197 452,361,020 3389.44 30319.66 2381.83 303119.60 69.76

1990 22,523,984 719,014,210 2423.96 24275.23 2599.22 442908.70 113.57

2000 26,785,744 822,458,560 1357.07 12461.46 1981.11 475853.90 78.81

2002 28,178,674 878,540,860 1125.82 10056.19 1817.13 505344.80 73.71

2005 29,135,822 895,088,450 948.51 7941.62 1640.20 519362.50 72.54

2010 31,854,958 967,485,630 723.74 5688.66 1263.26 563602.40 64.29

2015 34,108,548 1,040,360,600 546.62 3909.82 876.57 615846.90 59.08

2020 36,271,344 1,110,751,400 426.93 2744.30 619.97 663844.10 56.94

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 2,557 -45,058,820 -215.60 -2963.05 -207.39 -26035.00 -3.79

1990 8,010 -67,006,210 -122.95 -2234.93 -192.78 -34724.70 -5.75

2000 0 -75,101,120 -50.08 -1118.75 -136.16 -37685.50 -5.48

2002 0 -79,719,430 -29.94 -881.31 -109.91 -39900.00 -5.44

2005 -1,774,438 -139,646,250 -71.14 -1156.34 -154.85 -71995.60 -8.84

2010 -2,105,178 -154,299,470 -43.98 -818.98 -78.78 -77638.20 -7.75

2015 -2,681,268 -178,640,000 -33.96 -600.41 -61.22 -93302.50 -9.23

2020 -3,396,152 -207,707,000 -27.96 -454.64 -50.16 -109511.40 -10.59

Cal. Year Population VMT ROG_Tot1

CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.02% -9.06% -5.98% -8.90% -8.01% -7.91% -5.15%

1990 0.04% -8.52% -4.83% -8.43% -6.90% -7.27% -4.82%

2000 0.00% -8.37% -3.56% -8.24% -6.43% -7.34% -6.50%

2002 0.00% -8.32% -2.59% -8.06% -5.70% -7.32% -6.88%

2005 -5.74% -13.50% -6.98% -12.71% -8.63% -12.17% -10.86%

2010 -6.20% -13.75% -5.73% -12.58% -5.87% -12.11% -10.76%

2015 -7.29% -14.65% -5.85% -13.31% -6.53% -13.16% -13.51%

2020 -8.56% -15.75% -6.15% -14.21% -7.48% -14.16% -15.68%

ROG_Tot1

 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

(Calculated Using EMFAC2007 draft ver 2.226)

Difference (Ver. 2.226 - Ver. 2.225) in Statewide Emission Inventories (tons per day)

Percentage Change in Statewide Emission Inventories (relative to Ver. 2.225)

Statewide Summer Episodic On-Road Motor Vehicle Inventories 

(Calculated Using EMFAC2007 draft ver 2.225)

Statewide Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG VMTs
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-21

Table 7: Sacramento Valley Air Basin New VMT and Emission Impacts 

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1189906 39432972 303.10 2854.83 213.30 25924.68 6.37

1990 1761329 61722380 208.55 2171.95 232.02 37811.89 10.91

2000 2069264 67513488 119.25 1125.49 180.22 40118.05 7.17

2002 2254476 74678744 101.78 937.45 168.17 43740.23 6.74

2005 2566627 82908240 94.73 805.89 161.63 48876.33 7.00

2010 2862687 91412848 73.65 584.40 120.75 53269.45 6.11

2015 3173468 103683800 54.92 397.14 83.15 60338.51 5.72

2020 3454848 113224960 42.33 277.45 57.98 66815.88 5.63

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1189906 38993796 300.72 2820.04 210.89 25655.24 6.27

1990 1761329 61012160 206.77 2141.71 229.12 37393.59 10.73

2000 2069264 66786188 118.45 1109.86 177.85 39694.47 7.05

2002 2254476 73893392 101.21 924.39 166.00 43286.40 6.62

2005 2564842 82002616 94.15 793.90 159.23 48335.57 6.87

2010 2858330 90350352 73.18 574.63 118.59 52628.00 5.98

2015 3158083 102194780 54.38 388.92 81.21 59424.96 5.59

2020 3446194 111822660 42.07 272.31 56.78 65951.75 5.52

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 -439176 -2.37 -34.79 -2.41 -269.44 -0.10

1990 0 -710220 -1.78 -30.23 -2.91 -418.30 -0.18

2000 0 -727300 -0.79 -15.63 -2.37 -423.58 -0.12

2002 0 -785352 -0.57 -13.06 -2.17 -453.83 -0.11

2005 -1785 -905624 -0.57 -12.00 -2.40 -540.76 -0.13

2010 -4357 -1062496 -0.47 -9.76 -2.16 -641.45 -0.13

2015 -15385 -1489020 -0.54 -8.22 -1.95 -913.55 -0.13

2020 -8654 -1402300 -0.26 -5.14 -1.20 -864.13 -0.11

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% -1.11% -0.78% -1.22% -1.13% -1.04% -1.56%

1990 0.00% -1.15% -0.85% -1.39% -1.25% -1.11% -1.69%

2000 0.00% -1.08% -0.66% -1.39% -1.32% -1.06% -1.72%

2002 0.00% -1.05% -0.56% -1.39% -1.29% -1.04% -1.67%

2005 -0.07% -1.09% -0.60% -1.49% -1.48% -1.11% -1.88%

2010 -0.15% -1.16% -0.64% -1.67% -1.79% -1.20% -2.06%

2015 -0.48% -1.44% -0.98% -2.07% -2.34% -1.51% -2.25%

2020 -0.25% -1.24% -0.61% -1.85% -2.08% -1.29% -1.90%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.226 - Ver. 2.225) in Sacramento Emission Inventories (tons per day)

Percentage Change in Sacramento Emission Inventories (relative to Ver. 2.225)

Sacramento Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.225)

Sacramento Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG VMT

(Calculated Using EMFAC2007 draft ver 2.226)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-22

Table 8: San Diego Air Basin New VMT and Emission Impacts

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1097560 33909908 299.80 2720.07 172.04 23744.43 3.60

1990 1874269 65479136 203.76 2153.91 198.10 40895.29 6.30

2000 2227749 74069576 105.04 1029.44 140.46 41771.38 5.00

2002 2373918 80020584 87.65 846.07 125.67 45127.00 4.99

2005 2654406 87498144 78.65 724.04 114.59 49545.58 5.32

2010 2859402 92355784 58.93 506.80 87.12 51998.42 5.13

2015 3090088 99320864 45.71 352.70 63.24 56011.39 5.10

2020 3248809 103131030 37.60 259.02 47.85 58635.43 5.17

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1097560 33496236 297.15 2685.02 169.93 23470.72 3.55

1990 1874269 64680348 202.07 2126.32 195.56 40414.38 6.20

2000 2227749 73166000 104.39 1016.39 138.54 41279.64 4.91

2002 2373918 79044400 87.20 835.47 124.00 44595.10 4.90

2005 2571104 83761520 75.88 692.42 109.90 47455.96 5.08

2010 2748386 87558408 56.67 482.32 82.72 49319.84 4.84

2015 2966158 94097624 43.91 335.17 60.13 53104.29 4.81

2020 3177690 100357630 36.28 247.97 46.11 57053.48 4.97

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 -413672 -2.65 -35.05 -2.11 -273.71 -0.05

1990 0 -798788 -1.69 -27.59 -2.54 -480.91 -0.10

2000 0 -903576 -0.65 -13.05 -1.92 -491.74 -0.08

2002 0 -976184 -0.45 -10.60 -1.67 -531.90 -0.08

2005 -83302 -3736624 -2.77 -31.62 -4.69 -2089.62 -0.24

2010 -111016 -4797376 -2.27 -24.47 -4.39 -2678.58 -0.29

2015 -123930 -5223240 -1.79 -17.53 -3.12 -2907.10 -0.29

2020 -71119 -2773400 -1.31 -11.04 -1.74 -1581.95 -0.20

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% -1.22% -0.88% -1.29% -1.22% -1.15% -1.42%

1990 0.00% -1.22% -0.83% -1.28% -1.28% -1.18% -1.59%

2000 0.00% -1.22% -0.62% -1.27% -1.37% -1.18% -1.70%

2002 0.00% -1.22% -0.52% -1.25% -1.33% -1.18% -1.69%

2005 -3.14% -4.27% -3.52% -4.37% -4.10% -4.22% -4.52%

2010 -3.88% -5.19% -3.84% -4.83% -5.04% -5.15% -5.70%

2015 -4.01% -5.26% -3.92% -4.97% -4.93% -5.19% -5.69%

2020 -2.19% -2.69% -3.49% -4.26% -3.63% -2.70% -3.93%

ROG_Tot1

 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2

 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.226 - Ver. 2.225) in San Diego Emission Inventories (tons per day)

Percentage Change in San Diego Emission Inventories (relative to Ver. 2.225)

San Diego Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.225)

San Diego Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG VMTs

(Calculated Using EMFAC2007 draft ver 2.226)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-23

Table 9: San Francisco Air Basin New VMT and Emission Impacts

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 3577805 113122960 853.62 7929.08 590.98 70074.33 10.93

1990 4628184 152582580 481.28 5057.39 503.60 85561.60 15.02

2000 5519282 177297100 261.09 2515.25 340.34 94893.51 11.27

2002 5644236 183115630 220.05 2128.45 313.85 98220.21 10.87

2005 6003726 191004560 183.13 1674.32 267.53 102661.90 11.30

2010 6757176 213706530 141.05 1242.50 202.47 122057.50 11.82

2015 7193950 227056940 102.96 849.52 139.09 132051.80 11.87

2020 7683764 243221500 77.72 587.99 98.14 141849.50 12.14

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 3577805 104633350 811.63 7313.42 546.00 65112.39 9.87

1990 4628184 140980770 459.30 4660.59 463.01 79310.57 13.42

2000 5519282 164071820 251.76 2326.24 311.13 88033.75 10.06

2002 5644236 169344130 212.71 1964.83 286.59 91055.96 9.72

2005 5964264 175417250 177.12 1532.31 242.99 94489.30 10.01

2010 6401483 186231760 132.16 1089.44 178.65 106644.50 10.07

2015 6842192 199615200 96.80 740.79 122.56 116166.60 10.10

2020 7203858 209594370 72.97 509.05 86.28 122493.60 10.20

Cal. Year Population VMT(miles) ROG_Tot1

CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 -8489610 -42.00 -615.66 -44.99 -4961.94 -1.06

1990 0 -11601810 -21.97 -396.80 -40.59 -6251.03 -1.59

2000 0 -13225280 -9.33 -189.01 -29.21 -6859.76 -1.21

2002 0 -13771500 -7.34 -163.62 -27.25 -7164.25 -1.16

2005 -39462 -15587310 -6.01 -142.01 -24.54 -8172.60 -1.28

2010 -355693 -27474770 -8.90 -153.06 -23.83 -15413.00 -1.75

2015 -351758 -27441740 -6.16 -108.73 -16.53 -15885.20 -1.77

2020 -479906 -33627130 -4.75 -78.94 -11.85 -19355.90 -1.94

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% -7.50% -4.92% -7.76% -7.61% -7.08% -9.72%

1990 0.00% -7.60% -4.57% -7.85% -8.06% -7.31% -10.62%

2000 0.00% -7.46% -3.57% -7.51% -8.58% -7.23% -10.72%

2002 0.00% -7.52% -3.33% -7.69% -8.68% -7.29% -10.63%

2005 -0.66% -8.16% -3.28% -8.48% -9.17% -7.96% -11.35%

2010 -5.26% -12.86% -6.31% -12.32% -11.77% -12.63% -14.81%

2015 -4.89% -12.09% -5.99% -12.80% -11.88% -12.03% -14.91%

2020 -6.25% -13.83% -6.11% -13.43% -12.08% -13.65% -15.99%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.226 - Ver. 2.225) in San Francisco Emission Inventories (tons per day)

Percentage Change in San Francisco Emission Inventories (relative to Ver. 2.225)

San Francisco Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.225)

San Francisco Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG VMTs

(Calculated Using EMFAC2007 draft ver 2.226)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-24

Table 10: San Joaquin Valley Air Basin New VMT and Emission Impacts

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1023520 38087232 271.20 2730.16 256.65 29347.22 14.49

1990 1679639 63364384 231.95 2423.36 337.54 46353.51 24.66

2000 2330556 82586816 154.83 1464.79 329.20 57045.61 16.00

2002 2487499 89559584 129.28 1186.23 315.67 60746.58 14.20

2005 2830626 99974768 121.26 1023.58 316.77 68100.70 14.12

2010 3199563 112108190 92.83 728.81 236.88 74139.71 10.75

2015 3615226 130570590 69.66 495.88 166.60 86958.69 9.21

2020 4024302 146839180 54.26 350.59 119.07 99459.26 8.57

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1023520 35562160 258.74 2540.86 241.26 27640.65 13.54

1990 1679639 59095444 221.82 2254.52 317.67 43622.46 23.06

2000 2330556 77028680 149.58 1362.70 309.37 53628.51 14.82

2002 2487499 83510824 125.65 1103.89 297.27 57072.38 13.14

2005 2729342 89859968 114.61 921.78 288.39 61565.61 12.60

2010 3159172 103175800 90.84 675.24 222.08 68293.25 9.88

2015 3468090 116115740 67.54 451.85 152.23 77351.02 8.18

2020 3811652 129483420 52.37 315.08 106.97 87781.16 7.48

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 -2525072 -12.45 -189.30 -15.39 -1706.57 -0.95

1990 0 -4268940 -10.13 -168.85 -19.87 -2731.05 -1.60

2000 0 -5558136 -5.26 -102.09 -19.83 -3417.10 -1.18

2002 0 -6048760 -3.64 -82.34 -18.40 -3674.20 -1.06

2005 -101284 -10114800 -6.65 -101.80 -28.38 -6535.09 -1.51

2010 -40391 -8932390 -1.98 -53.57 -14.79 -5846.46 -0.87

2015 -147136 -14454850 -2.12 -44.03 -14.36 -9607.67 -1.03

2020 -212650 -17355760 -1.89 -35.51 -12.10 -11678.10 -1.09

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% -6.63% -4.59% -6.93% -6.00% -5.82% -6.55%

1990 0.00% -6.74% -4.37% -6.97% -5.89% -5.89% -6.50%

2000 0.00% -6.73% -3.40% -6.97% -6.02% -5.99% -7.36%

2002 0.00% -6.75% -2.81% -6.94% -5.83% -6.05% -7.46%

2005 -3.58% -10.12% -5.48% -9.95% -8.96% -9.60% -10.70%

2010 -1.26% -7.97% -2.14% -7.35% -6.25% -7.89% -8.09%

2015 -4.07% -11.07% -3.05% -8.88% -8.62% -11.05% -11.14%

2020 -5.28% -11.82% -3.48% -10.13% -10.16% -11.74% -12.76%

ROG_Tot1

 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.226 - Ver. 2.225) in San Joaquin Emission Inventories (tons per day)

Percentage Change in San Joaquin Emission Inventories (relative to Ver. 2.225)

San Joaquin Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.225)

San Joaquin Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG VMTs

(Calculated Using EMFAC2007 draft ver 2.226)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-25

Table11: South Coast Air Basin New VMT and Emission Impacts

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 6132212 212274690 1444.87 13076.57 974.36 138027.20 21.90

1990 9485851 332536610 1055.82 10900.81 1024.42 196327.50 32.95

2000 11074958 374707840 563.05 5478.85 721.29 205289.90 25.70

2002 11606219 399479680 452.53 4345.55 632.13 217598.10 24.81

2005 12648746 431110880 387.47 3528.80 562.43 235094.50 26.21

2010 13569852 455681220 279.78 2424.07 415.72 246294.50 24.96

2015 14488933 482021250 212.99 1694.85 287.62 266581.40 24.80

2020 15463265 514247580 168.23 1209.94 204.30 285327.50 25.04

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 6132212 180033150 1293.57 11068.61 836.95 119653.70 20.28

1990 9485851 284595070 970.75 9331.86 902.00 172100.40 30.65

2000 11074958 321947740 530.31 4701.98 641.59 179635.30 22.91

2002 11606219 343506050 434.20 3739.80 571.44 190507.20 21.88

2005 11270981 329753600 336.91 2705.51 475.15 184343.70 21.02

2010 12119336 350421920 250.49 1868.12 371.71 195277.20 20.02

2015 12683695 362652060 192.04 1294.47 260.23 207396.40 19.04

2020 13184638 376647260 150.97 909.32 183.10 217009.20 18.38

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 -32241540 -151.30 -2007.96 -137.41 -18373.50 -1.63

1990 0 -47941540 -85.07 -1568.95 -122.42 -24227.10 -2.30

2000 0 -52760100 -32.74 -776.87 -79.71 -25654.60 -2.79

2002 0 -55973630 -18.34 -605.75 -60.68 -27090.90 -2.93

2005 -1377765 -101357280 -50.57 -823.29 -87.28 -50750.80 -5.19

2010 -1450516 -105259300 -29.29 -555.95 -44.01 -51017.30 -4.94

2015 -1805238 -119369190 -20.95 -400.39 -27.39 -59185.00 -5.76

2020 -2278627 -137600320 -17.26 -300.62 -21.20 -68318.30 -6.66

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% -15.19% -10.47% -15.36% -14.10% -13.31% -7.43%

1990 0.00% -14.42% -8.06% -14.39% -11.95% -12.34% -6.97%

2000 0.00% -14.08% -5.82% -14.18% -11.05% -12.50% -10.86%

2002 0.00% -14.01% -4.05% -13.94% -9.60% -12.45% -11.80%

2005 -10.89% -23.51% -13.05% -23.33% -15.52% -21.59% -19.80%

2010 -10.69% -23.10% -10.47% -22.93% -10.59% -20.71% -19.79%

2015 -12.46% -24.76% -9.84% -23.62% -9.52% -22.20% -23.23%

2020 -14.74% -26.76% -10.26% -24.85% -10.38% -23.94% -26.61%

ROG_Tot1

 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2

 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.226 - Ver. 2.225) in South Coast Emission Inventories (tons per day)

Percentage Change in South Coast Emission Inventories (relative to Ver. 2.225)

South Coast Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.225)

South Coast Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG VMTs

(Calculated Using EMFAC2007 draft ver 2.226)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-26

Table 12: Statewide Emissions Impacts from New Speeds

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 14820197 452361020 3389.44 30319.66 2381.83 303119.60 69.76

1990 22523984 719014210 2423.96 24275.23 2599.22 442908.70 113.57

2000 26785744 822458560 1357.07 12461.46 1981.11 475853.90 78.81

2002 28178674 878540860 1125.82 10056.19 1817.13 505344.80 73.71

2005 29135822 895088450 948.51 7941.62 1640.20 519362.50 72.54

2010 31854958 967485630 723.74 5688.66 1263.26 563602.40 64.29

2015 34108548 1040360600 546.62 3909.82 876.57 615846.90 59.08

2020 36271344 1110751400 426.93 2744.30 619.97 663844.10 56.94

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 14820197 452361020 3391.44 30338.42 2381.20 303363.40 69.77

1990 22523984 719014210 2425.25 24292.48 2599.45 443269.30 113.58

2000 26785744 822458560 1384.34 12713.99 1992.36 491034.00 79.62

2002 28178674 878540860 1147.14 10263.45 1827.72 522520.90 74.60

2005 29135822 895088450 963.08 8090.12 1647.95 536017.40 73.46

2010 31854958 967485630 731.12 5749.98 1269.81 575405.80 65.36

2015 34108548 1040360600 549.28 3924.37 880.74 623504.50 59.72

2020 36271344 1110751400 428.95 2755.23 622.75 673717.30 57.64

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 0 2.00 18.76 -0.63 243.80 0.02

1990 0 0 1.29 17.25 0.24 360.60 0.02

2000 0 0 27.27 252.53 11.24 15180.10 0.81

2002 0 0 21.32 207.26 10.59 17176.10 0.89

2005 0 0 14.57 148.50 7.75 16654.90 0.92

2010 0 0 7.38 61.32 6.55 11803.40 1.07

2015 0 0 2.66 14.55 4.18 7657.60 0.64

2020 0 0 2.02 10.93 2.77 9873.20 0.69

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% 0.00% 0.06% 0.06% -0.03% 0.08% 0.02%

1990 0.00% 0.00% 0.05% 0.07% 0.01% 0.08% 0.02%

2000 0.00% 0.00% 2.01% 2.03% 0.57% 3.19% 1.03%

2002 0.00% 0.00% 1.89% 2.06% 0.58% 3.40% 1.20%

2005 0.00% 0.00% 1.54% 1.87% 0.47% 3.21% 1.27%

2010 0.00% 0.00% 1.02% 1.08% 0.52% 2.09% 1.66%

2015 0.00% 0.00% 0.49% 0.37% 0.48% 1.24% 1.08%

2020 0.00% 0.00% 0.47% 0.40% 0.45% 1.49% 1.22%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

(Calculated Using EMFAC2007 draft ver 2.227)

Difference (Ver. 2.227 - Ver. 2.226) in Statewide Emission Inventories (tons per day)

Percentage Change in Statewide Emission Inventories (relative to Ver. 2.226)

Statewide Summer Episodic On-Road Motor Vehicle Inventories 

(Calculated Using EMFAC2007 draft ver 2.226)

Statewide Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG Speeds
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-27

Table 13: Sacramento Valley Air Basin Emission Impacts from New Speeds 

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1189906 38993796 300.72 2820.04 210.89 25655.24 6.27

1990 1761329 61012160 206.77 2141.71 229.12 37393.59 10.73

2000 2069264 66786188 118.45 1109.86 177.85 39694.47 7.05

2002 2254476 73893392 101.21 924.39 166.00 43286.40 6.62

2005 2564842 82002616 94.15 793.90 159.23 48335.57 6.87

2010 2858330 90350352 73.18 574.63 118.59 52628.00 5.98

2015 3158083 102194780 54.38 388.92 81.21 59424.96 5.59

2020 3446194 111822660 42.07 272.31 56.78 65951.75 5.52

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1189906 38993796 301.11 2835.63 211.14 25699.52 6.27

1990 1761329 61012160 207.01 2150.16 229.46 37479.71 10.73

2000 2069264 66786188 119.02 1118.47 178.61 40099.35 7.06

2002 2254476 73893392 101.91 934.47 166.85 43942.66 6.65

2005 2564842 82002616 94.65 801.24 159.88 48973.60 6.89

2010 2858330 90350352 73.27 575.61 118.89 52912.88 5.98

2015 3158083 102194780 54.47 388.58 81.38 59809.62 5.59

2020 3446194 111822660 42.06 269.64 56.82 65935.05 5.49

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 0 0.39 15.59 0.26 44.28 0.00

1990 0 0 0.25 8.45 0.34 86.12 0.00

2000 0 0 0.56 8.60 0.75 404.88 0.01

2002 0 0 0.69 10.07 0.84 656.26 0.02

2005 0 0 0.50 7.34 0.64 638.03 0.02

2010 0 0 0.09 0.98 0.30 284.88 -0.01

2015 0 0 0.09 -0.34 0.17 384.66 0.00

2020 0 0 -0.01 -2.67 0.05 -16.70 -0.03

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% 0.00% 0.13% 0.55% 0.12% 0.17% 0.04%

1990 0.00% 0.00% 0.12% 0.39% 0.15% 0.23% 0.02%

2000 0.00% 0.00% 0.48% 0.78% 0.42% 1.02% 0.20%

2002 0.00% 0.00% 0.69% 1.09% 0.51% 1.52% 0.36%

2005 0.00% 0.00% 0.53% 0.92% 0.40% 1.32% 0.31%

2010 0.00% 0.00% 0.12% 0.17% 0.25% 0.54% -0.11%

2015 0.00% 0.00% 0.16% -0.09% 0.21% 0.65% 0.01%

2020 0.00% 0.00% -0.03% -0.98% 0.08% -0.03% -0.63%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.227 - Ver. 2.226) in Sacramento Emission Inventories (tons per day)

Percentage Change in Sacramento Emission Inventories (relative to Ver. 2.226)

Sacramento Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.226)

Sacramento Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG Speeds

(Calculated Using EMFAC2007 draft ver 2.227)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-28

Table 14: San Diego Air Basin Emission Impacts from New Speeds

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1097560 33496236 297.15 2685.02 169.93 23470.72 3.55

1990 1874269 64680348 202.07 2126.32 195.56 40414.38 6.20

2000 2227749 73166000 104.39 1016.39 138.54 41279.64 4.91

2002 2373918 79044400 87.20 835.47 124.00 44595.10 4.90

2005 2571104 83761520 75.88 692.42 109.90 47455.96 5.08

2010 2748386 87558408 56.67 482.32 82.72 49319.84 4.84

2015 2966158 94097624 43.91 335.17 60.13 53104.29 4.81

2020 3177690 100357630 36.28 247.97 46.11 57053.48 4.97

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1097560 33496236 297.15 2685.02 169.93 23470.72 3.55

1990 1874269 64680348 202.07 2126.32 195.56 40414.38 6.20

2000 2227749 73166000 104.39 1016.39 138.54 41279.64 4.91

2002 2373918 79044400 87.72 840.83 124.32 45057.07 4.93

2005 2571104 83761520 76.24 696.02 110.10 47881.50 5.11

2010 2748386 87558408 56.81 484.11 82.78 49584.72 4.86

2015 2966158 94097624 44.19 339.19 60.27 54017.91 4.90

2020 3177690 100357630 36.43 250.64 46.21 57845.01 5.04

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 0 0.00 0.00 0.00 0.00 0.00

1990 0 0 0.00 0.00 0.00 0.00 0.00

2000 0 0 0.00 0.00 0.00 0.00 0.00

2002 0 0 0.52 5.36 0.32 461.97 0.03

2005 0 0 0.36 3.60 0.21 425.54 0.03

2010 0 0 0.14 1.79 0.06 264.88 0.02

2015 0 0 0.28 4.02 0.14 913.62 0.09

2020 0 0 0.15 2.66 0.10 791.53 0.08

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

1990 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

2000 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

2002 0.00% 0.00% 0.60% 0.64% 0.26% 1.04% 0.51%

2005 0.00% 0.00% 0.48% 0.52% 0.19% 0.90% 0.52%

2010 0.00% 0.00% 0.25% 0.37% 0.07% 0.54% 0.47%

2015 0.00% 0.00% 0.63% 1.20% 0.24% 1.72% 1.84%

2020 0.00% 0.00% 0.41% 1.07% 0.22% 1.39% 1.56%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.227 - Ver. 2.226) in San Diego Emission Inventories (tons per day)

Percentage Change in San Diego Emission Inventories (relative to Ver. 2.226)

San Diego Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.226)

San Diego Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG Speeds

(Calculated Using EMFAC2007 draft ver 2.227)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-29

Table 15: San Francisco Air Basin Emission Impacts from New Speeds

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 3577805 104633350 811.63 7313.42 546.00 65112.39 9.87

1990 4628184 140980770 459.30 4660.59 463.01 79310.57 13.42

2000 5519282 164071820 251.76 2326.24 311.13 88033.75 10.06

2002 5644236 169344130 212.71 1964.83 286.59 91055.96 9.72

2005 5964264 175417250 177.12 1532.31 242.99 94489.30 10.01

2010 6401483 186231760 132.16 1089.44 178.65 106644.50 10.07

2015 6842192 199615200 96.80 740.79 122.56 116166.60 10.10

2020 7203858 209594370 72.97 509.05 86.28 122493.60 10.20

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 3577805 104633350 811.63 7313.42 546.00 65112.39 9.87

1990 4628184 140980770 459.30 4660.59 463.01 79310.57 13.42

2000 5519282 164071820 259.40 2416.68 317.13 93331.35 10.28

2002 5644236 169344130 219.54 2041.04 292.02 96807.51 9.95

2005 5964264 175417250 182.01 1589.66 246.91 100448.90 10.28

2010 6401483 186231760 131.77 1083.81 179.30 106597.10 9.98

2015 6842192 199615200 96.03 725.23 122.57 114287.00 9.86

2020 7203858 209594370 72.73 498.46 86.38 121893.30 10.05

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 0 0.00 0.00 0.00 0.00 0.00

1990 0 0 0.00 0.00 0.00 0.00 0.00

2000 0 0 7.63 90.45 5.99 5297.60 0.22

2002 0 0 6.83 76.21 5.43 5751.55 0.24

2005 0 0 4.89 57.35 3.91 5959.60 0.27

2010 0 0 -0.39 -5.63 0.65 -47.40 -0.09

2015 0 0 -0.77 -15.56 0.01 -1879.60 -0.23

2020 0 0 -0.24 -10.58 0.10 -600.30 -0.15

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

1990 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

2000 0.00% 0.00% 3.03% 3.89% 1.93% 6.02% 2.16%

2002 0.00% 0.00% 3.21% 3.88% 1.89% 6.32% 2.44%

2005 0.00% 0.00% 2.76% 3.74% 1.61% 6.31% 2.67%

2010 0.00% 0.00% -0.29% -0.52% 0.37% -0.04% -0.91%

2015 0.00% 0.00% -0.80% -2.10% 0.01% -1.62% -2.32%

2020 0.00% 0.00% -0.33% -2.08% 0.11% -0.49% -1.51%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.227 - Ver. 2.226) in San Francisco Emission Inventories (tons per day)

Percentage Change in San Francisco Emission Inventories (relative to Ver. 2.226)

San Francisco Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.226)

San Francisco Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG Speeds

(Calculated Using EMFAC2007 draft ver 2.227)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-30

Table 16: San Joaquin Valley Air Basin Emission Impacts from New Speeds

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1023520 35562160 258.74 2540.86 241.26 27640.65 13.54

1990 1679639 59095444 221.82 2254.52 317.67 43622.46 23.06

2000 2330556 77028680 149.58 1362.70 309.37 53628.51 14.82

2002 2487499 83510824 125.65 1103.89 297.27 57072.38 13.14

2005 2729342 89859968 114.61 921.78 288.39 61565.61 12.60

2010 3159172 103175800 90.84 675.24 222.08 68293.25 9.88

2015 3468090 116115740 67.54 451.85 152.23 77351.02 8.18

2020 3811652 129483420 52.37 315.08 106.97 87781.16 7.48

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 1023520 35562160 258.70 2527.80 240.91 27637.42 13.54

1990 1679639 59095444 221.85 2249.25 317.41 43618.66 23.06

2000 2330556 77028680 150.75 1374.49 309.54 54170.14 14.83

2002 2487499 83510824 126.64 1115.36 297.49 57753.48 13.15

2005 2729342 89859968 115.45 932.66 288.57 62379.82 12.63

2010 3159172 103175800 91.47 684.46 222.24 69335.46 9.94

2015 3468090 116115740 68.11 460.72 152.40 79022.63 8.30

2020 3811652 129483420 52.73 320.60 107.07 89350.41 7.59

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 0 -0.04 -13.06 -0.34 -3.23 0.00

1990 0 0 0.03 -5.27 -0.25 -3.80 0.00

2000 0 0 1.18 11.80 0.16 541.63 0.01

2002 0 0 0.99 11.46 0.22 681.10 0.01

2005 0 0 0.84 10.89 0.18 814.21 0.02

2010 0 0 0.63 9.22 0.16 1042.21 0.05

2015 0 0 0.57 8.88 0.16 1671.61 0.12

2020 0 0 0.35 5.51 0.11 1569.25 0.11

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% 0.00% -0.02% -0.51% -0.14% -0.01% 0.00%

1990 0.00% 0.00% 0.01% -0.23% -0.08% -0.01% 0.01%

2000 0.00% 0.00% 0.79% 0.87% 0.05% 1.01% 0.04%

2002 0.00% 0.00% 0.79% 1.04% 0.07% 1.19% 0.09%

2005 0.00% 0.00% 0.73% 1.18% 0.06% 1.32% 0.19%

2010 0.00% 0.00% 0.69% 1.37% 0.07% 1.53% 0.53%

2015 0.00% 0.00% 0.85% 1.96% 0.11% 2.16% 1.43%

2020 0.00% 0.00% 0.67% 1.75% 0.10% 1.79% 1.49%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.227 - Ver. 2.226) in San Joaquin Emission Inventories (tons per day)

Percentage Change in San Joaquin Emission Inventories (relative to Ver. 2.226)

San Joaquin Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.226)

San Joaquin Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG Speeds

(Calculated Using EMFAC2007 draft ver 2.227)
 March 17, 2006 

Appendix F - Activity Tech Memo.doc F-31

Table 17: South Coast Air Basin Emission Impacts from New Speeds

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 6132212 180033150 1293.57 11068.61 836.95 119653.70 20.28

1990 9485851 284595070 970.75 9331.86 902.00 172100.40 30.65

2000 11074958 321947740 530.31 4701.98 641.59 179635.30 22.91

2002 11606219 343506050 434.20 3739.80 571.44 190507.20 21.88

2005 11270981 329753600 336.91 2705.51 475.15 184343.70 21.02

2010 12119336 350421920 250.49 1868.12 371.71 195277.20 20.02

2015 12683695 362652060 192.04 1294.47 260.23 207396.40 19.04

2020 13184638 376647260 150.97 909.32 183.10 217009.20 18.38

Cal. Year Population VMT*(1000) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 6132212 180033150 1293.57 11068.61 836.95 119653.70 20.28

1990 9485851 284595070 970.75 9331.86 902.00 172100.40 30.65

2000 11074958 321947740 545.89 4824.47 645.58 188003.30 23.41

2002 11606219 343506050 445.05 3830.92 575.38 199174.60 22.37

2005 11270981 329753600 343.60 2762.98 477.88 192241.40 21.50

2010 12119336 350421920 254.92 1912.78 373.64 204573.60 20.64

2015 12683695 362652060 193.27 1308.38 261.55 213273.30 19.43

2020 13184638 376647260 151.86 921.66 184.01 223890.50 18.89

Cal. Year Population VMT(miles) ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0 0 0.00 0.00 0.00 0.00 0.00

1990 0 0 0.00 0.00 0.00 0.00 0.00

2000 0 0 15.58 122.49 3.99 8368.00 0.49

2002 0 0 10.86 91.12 3.94 8667.40 0.49

2005 0 0 6.70 57.48 2.73 7897.70 0.48

2010 0 0 4.43 44.66 1.92 9296.40 0.62

2015 0 0 1.23 13.91 1.31 5876.90 0.39

2020 0 0 0.89 12.33 0.92 6881.30 0.51

Cal. Year Population VMT ROG_Tot1CO_Tot NOx_Tot CO2_Tot PM10_Tot2

1980 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

1990 0.00% 0.00% 0.00% 0.00% 0.00% 0.00% 0.00%

2000 0.00% 0.00% 2.94% 2.61% 0.62% 4.66% 2.16%

2002 0.00% 0.00% 2.50% 2.44% 0.69% 4.55% 2.23%

2005 0.00% 0.00% 1.99% 2.12% 0.57% 4.28% 2.26%

2010 0.00% 0.00% 1.77% 2.39% 0.52% 4.76% 3.09%

2015 0.00% 0.00% 0.64% 1.07% 0.50% 2.83% 2.07%

2020 0.00% 0.00% 0.59% 1.36% 0.50% 3.17% 2.77%

ROG_Tot1 - This includes running, starting, idle exhaust emissions and emissions from all

evaporative processes.

PM10_Tot2 - Total emissions from running, starting, idle processes, and from tire wear and

brake wear.

Difference (Ver. 2.227 - Ver. 2.226) in South Coast Emission Inventories (tons per day)

Percentage Change in South Coast Emission Inventories (relative to Ver. 2.226)

South Coast Summer Episodic On-Road Motor Vehicle Inventories

(Calculated Using EMFAC2007 draft ver 2.226)

South Coast Summer Episodic On-Road Motor Vehicle Inventories With Changes to COG Speeds

(Calculated Using EMFAC2007 draft ver 2.227)
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Appendix F - Activity Tech Memo.doc F-32

APPENDIX: VMT Matching Algorithm 

This Appendix was taken from EMFAC Modeling Change Technical Memo, “Updating 

Estimates of Vehicle Miles Traveled,” July 2002, Appendix 1, pages 31 –36. Minor edits were 

made to reflect the addition of base years 2000, 2001, 2002, and 2003. 

New VMT is updated in the EMFAC model using a VMT matching algorithm. Key to 

understanding the VMT matching algorithm is that VMT is the product of the vehicle 

population, vehicle accrual and weekday adjustment factors. 

VMTcy,a,v,f = (POPcy,a,v,f,age *ACCRUALa,v,f,age) * WAFv (1) 

where: 

VMTcy,a,v,f = VMT for a given calendar year, geographic area, vehicle class, and fuel type. 

POPcy,a,v,f,age = Population for a given calendar year, geographic area, vehicle class, fuel type, 

and vehicle age. 

WAFv = Weekday adjustment factors by vehicle class. 

The VMT matching algorithm first checks to determine if target VMTs have been supplied for 

base years 1999, 2000, 2001, 2002, or 2003. This is important in assessing whether accrual 

rates should be changed or not. This step is described below under the heading “Base year 

adjustments.” Next, the algorithm calculates VMTs for all forecast calendar years. If the base 

year VMT is changed, the new accrual rates are used in calculating the VMTs for the forecast 

years. The algorithm then compares the VMTs for the forecast years with target VMTs. If they 

are different, the vehicle population growth rates are adjusted to match the target VMTs. This 

step is described in the section titled “Forecast years.” 

Base year adjustments 

In EMFAC 2007 the base years are 1999 through 2003. These years are referred to as base 

years because the model contains vehicle population data for these calendar years. The 

vehicle populations for base years are determined from analyzing DMV vehicle registration 

data. For all other calendar years the vehicle population is calculated using either the back 

casting (1970-1998) or the forecasting (2004-2040) algorithm. Equation 1 (above) shows that 

the VMT for the base years (Base_VMT) is calculated from the product of the known vehicle 

population, vehicle accrual and the weekday adjustment factors. 

Base year adjustments to vehicle accrual rates are necessary when the Base_VMT calculated 

in the model using equation 1, is different than the target VMT submitted by the TPA. For 

example, suppose a TPA, using a transportation model, calculates that the target VMT in 2000 

is 1,250,000 miles per day. The model must match this estimate along with those for future 

calendar years. To match the target VMT for CY 2000, only vehicle accrual rates can be 

changed while maintaining the relationship shown in equation 1. In the VMT matching 

algorithm, a ratio of the target versus base VMTs is calculated. This is noted as: 

Ratiov = Target_VMTv / Base_VMTv (2) 

where: 
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Appendix F - Activity Tech Memo.doc F-33

Subscript “v” refers to vehicle class. 

The ratio is then applied to the current accrual rates to calculate new accrual rates. 

New_ ACCRUALa,v,f,age = ACCRUALa,v,f,age * Ratiov (3) 

This calculation is done for each vehicle age, fuel type, and vehicle class and is specific to the 

geographic area. This is because accrual rates vary by these factors. These new accrual 

rates are then used in recalculating VMTs for all future years. These new VMTs are then 

used in subsequent calculation of population growth rates to match future year target VMTs. 

Forecast Years 

The EMFAC2007 model forecasts vehicle population and VMT estimates for calendar years 

2004-2040. VMT for future years is still calculated using equation 1 (above). However, in 

equation 1 vehicle population is now a function of the base year population (2003), population 

growth rates and vehicle attrition. For the purposes of explaining this algorithm assume that 

vehicle attrition is negligible. In this case the vehicle population in 2004 calendar year is 

simply a product of the known population in 2003 and the population growth rate in 2004. 

Similarly, the vehicle population in 2005 is a product of the forecasted population in 2004 and 

the population growth rate for calendar year 2005. If this process is simplified then one arrives 

at equation 4, which states that the population for a forecast year is simply a product of 2003 

calendar year and population growth rates. 

POP2004 = POP2003 * (1 + pgr2004) 

POP2005 = POP2004 * (1 + pgr2005) 

.. 

.. 

POP2005 ={POP2003 * (1 + pgr2004)} *(1 + pgr2005) 

POPcy,a,v,f,age = POP2003 * { (1 + pgr2004)*(1 + pgr2005)+...} (4) 

where: 

POP2003 = Vehicle population data from DMV 

Pgr2004 = Population growth rates for 2004 calendar year 

Pgr2005 = Population growth rates for 2005 calendar year 

 

Equation 4 shows in a simple way how vehicle populations are forecast. In reality the 

POP2003 varies by area, vehicle class, and fuel type. Hence, the population growth rates also 

vary by calendar year, area, vehicle class, and fuel type. The vehicle populations, calculated 

using equation 4, are then used in equation 1 to calculate VMT for a given calendar year. 

From this simple explanation on how VMTs are calculated for future years it is important to 

grasp that if a TPA submits a target VMTs for a forecast year this VMT can be matched by 

adjusting the population growth rates. For example, if a TPA supplies a target VMT estimate 

for 2005 calendar year this target VMT is matched by adjusting the population growth rates for 

2004 and 2005 calendar years. It is assumed that the vehicle population grows linearly 

between the base year (2003) and the forecast year (2005). The linear increase in population 
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Appendix F - Activity Tech Memo.doc F-34

growth rates results in a linear increase in VMT. This will become evident in the following 

example. 

The VMT matching algorithm can be explained by the following example where region X has 

only submitted a target VMT of 2500 miles per day for calendar year 2005. Table A-1 shows 

the population growth rates for region X. The growth rate for 2003 is 0 since this is a base 

year. Thereafter, the vehicle population grows by 10% in 2004 and 15% in 2005. In this 

example, assume that the VMT for 2003 calendar year, calculated as a product of the known 

vehicle population and vehicle accrual rate, is 1501.97 miles per day. Further, assume that 

VMT grows at the same rate as population growth rates. Note this is not always the case 

since shifts in the model year population distribution can result in a different VMT growth hence 

the need to iterate on the population growth rates.

Table A-1 Example Data for Region X 

 2003 2004 2005 

Population Growth Rates 0 0.1 0.15 

Modeled VMTs 1501.97 1652.17 1900 

Target VMT 2500 

In this example, the VMT matching algorithm first calculates VMTs for 2004 and 2005. These 

are shows as “Modeled VMTs” in Table A-1. Using equation 4 the VMT for 2004 is 1501.97 * 

(1+ 0.1) = 1652.17 miles per day. Similarly, the VMT for 2005 is 1652.17 (1+0.15) = 1900 mile 

per day. 

Having calculated “Modeled VMT” for calendar year 2005, the VMT algorithm notes that this 

estimate is different than the target VMT estimate. 

The VMT matching algorithm then proceeds through the following steps noted S1, S2 and so 

on. 

Begin loop 

S1: The model first calculated a ratio based on dividing the target VMT by the Modeled VMT 

for 2005. 

 Ratio = Target_VMT2005 / Modeled_VMT2005 = 2500/1900 = 1.3157895 

S2: Check for convergence. If the value of (Ratio – 1) is less than 0.00001 then skip further 

iterations. When this convergence criteria has been met it assumes that the modeled 

VMT for 2005 matches the target VMT. In this example, the Ratio is 1.3157895 hence 

proceed to the next step. 

S3: Calculate the current compounded growth factor for calendar year 2005. This 

compounded growth factor for 2005 is: gf = (1)*(1.1)*(1.15) = 1.265. 

S4: The compounded growth factor indicates that the VMT increases by 26.5% from 2003 to 

2005 calendar year. This compounded growth factor is then used to calculate a linear 
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Appendix F - Activity Tech Memo.doc F-35

growth factor (lgf) for calendar years 2004 and 2005. This growth factor assumes a linear 

and equal growth in VMT in calendar years 2004 and 2005. 

 The linear growth factor: lgf = EXP(ln(gf) / n) = 1.124722188 

In this equation n is number of years, which is 2 in this example. The linear growth factor 

indicates that the annualized growth rates is 12.5% for 2004 and 2005 calendar years. 

Note this lgf is for the growth in “Modeled VMT.” 

S5: The next step is to calculate what the annualized growth rate is for the new target VMT. 

This is done by calculating what the incremental growth factor is beyond what was 

calculated in S4. This is done by calculating the incremental growth factor: igf = 

EXP(ln(Ratio)/n) = 1.14707867. This incremental growth factor is then multiplied by the 

linear growth factor (lgf) to calculate the new annualized population growth rate. 

 Calculate new population growth rate: NGR = lgf * graf – 1 = 0.2901448 

In this example, the new annualized growth rate is 29% for 2004 and 2005 calendar years. 

This new growth rate is then used to calculate VMTs for calendar years 2004 and 2005. 

 

S6: Update growth rates and calculate new VMTs. Table A-2 shows the new growth rates for 

calendar years 2004 and 2005. Note the model assumes equal growth in 2004 and 2005 

calendar years. Hence, population and VMT will grow linearly between 2003 and 2005 

calendar years. In this example, the VMT for 2004 and 2005 are recalculated using the 

new population growth rates. Using equation 4, the new VMT for 2004 = 

1501.97*(1+0.29) =1937.76. This calculation is then repeated for calendar year 2005. 

Table A-2 Calculation of New Population Growth Rates and VMTs 

 2003 2004 2005 

NGR 0 0.2901448 0.2901448 

New VMT 1501.97 1937.76 2499.99 

 

S7: Goes to the top of the loop where additional checks are performed convergence. 

End loop 

In this example, the TPA submitted a target VMT for 2005. This VMT was matched is by 

adjusting the population growth rates for both 2004 and 2005 calendar years. These new 

growth rates were then used in calculating new VMTs for 2004 and 2005 calendar years. 

If the TPA had submitted target VMTs for 2005 and 2010 calendar years then the VMT 

matching algorithm would first match the 2005 VMT by following the steps outlined above. 

This would involve recalculating the VMTs for 2004 and 2005 calendar years assuming a linear 

and equal growth rate. To match the 2010 target VMT, the algorithm would recalculate VMTs 

for 2006, 2007, 2008, 2009 and 2010 calendar years. Again the algorithm would calculate a 

linear and equal growth rate for these years. It is important to note that since the VMT 

algorithm is matching VMTs for individual calendar years (for example 2005 and 2010), the 
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Appendix F - Activity Tech Memo.doc F-36

population growth rates for calendar years 2004-2005 may be different than that for calendar 

years 2006-2010. This reflects different growth assumptions. However, the growth rates 

within the calendar years is the same. 

The VMT matching algorithm then writes out changes to the population growth rate files, 

vehicle accrual rate files, and new forecasted VMTs for all future calendar years.