SCAG Region Heavy Duty Truck Model Southern California Region Heavy Duty Truck Model

SCAG Region Heavy Duty Truck ModelSCAG Region Heavy Duty Truck Model

Southern California Southern California RegionRegion

Heavy Duty Truck ModelHeavy Duty Truck Model


Issues and Needs

Heavy Duty Truck Movements Important Element of Regional Planning

600 Million Annual Tons of Goods - 70% by Truck

Trade, Transportation and Manufacturing 40% of Regional Employment

30% Growth in Goods Movement for Next 20 Years

Heavy Truck Movements in Many Regional Corridors

SCAG Model only Forecasts Light and Medium Duty Vehicles

HDT Movements Were Previously Estimated Only

Effects of Trucks on Traffic

Effects of Traffic on Trucks


Purpose of the Project

HDT Travel Demand Modeling Capabilities for the Region

Forecast HDT Volumes and Patterns

Develop Direct HDT Emissions Analysis

Planning and Programming Regional Truck

Improvements


Model Objectives

State of the Art HDT Model

HDT Model Integrated with SCAG Model

Relationship with Goods Movement and Economic Activity

Readily Available and Forecastable Input Data

Stratification by Truck Types

Stratification by Trip Type - Long Haul, Short Haul

Dynamic Simultaneous Assignment Procedure

Effects of Trucks in Terms of Passenger Car Equivalents

Outputs: Volumes, VMT, VHT, Speeds, Travel Time, Congestion


Project Components

Research and Data Collection

Model Component Development

Component Assembly and Incorporation with SCAG

Model

Model Validation

Model Application and Forecasts


Research and Data Collection

Over 70 Reports, Data Bases and Documents Reviewed Very Few Regional Models Have Comprehensive HDT Component Goods Movement Data Base Carrier Surveys Trip Diaries Shipper and Receiver Surveys Caltrans Truck Counts New Classification Counts Weigh-in-Motion Station Data Freeway PCE Speed/Flow Surveys Discussions with Subregions and COGs Technical Advisory Committee


Structure of the Model

Three Weight Categories by Gross Vehicle Weight (GVW) per ARB

Trip Generation for Internal Trips Trip Distribution for Internal Trips

External Trips Generation and Distribution

Special Generators, Generation and Distribution

Time of Day Factoring

Traffic Assignment

- Light-Heavy -- 8,500 to 14,000 GVW

- Medium-Heavy -- 14,000 to 33,000 GVW

- Heavy-Heavy -- Over 33,000 GVW


HDT Model Structure

S C A GS E D

H ig h w a yN e tw o rk

C a rrie r a ndS h ip p e r S urve ys

C o m m o d ityF low D ata

S IC D E TA IL

S E DD a tafo r H D T

1 d ig it 2 d ig it

P e rso nTrip

G e n era tio n

N e tw o rkD e ta ilF or H D T

Specia l G eneratorTrips P orts A irports In term odal Term inals

P e rso nTrip

D is tr ib u tion

A u toD a ily to4 -P e rio d

A u to A ss ig n m e nt

H D T Tru ckA ss ig n m e nt

F ina l To ta l Vo lu m e s

P C EA d ju s tm e nts

W IM S ta tio n S u rve ys

D a ily to P e rio d F a c to rs

H D T D a ily to 4 -P e rio d

IN T E R N A LH D T T R IP

D IS T R IB U T IO N

IN T E R N A LT R U C K T R IP

G E N E R ATIO N

E xte rn a lTrip s

F ric tio nF ac to rs

M od eC h o ice

H ig h w a yS K IM S


Trip Generation for Internal Trips Based on Shipper and Receiver Surveys

Telephone Surveys through Business Directory Standard Industrial Classification Codes (SIC) - One Digit Categories

- Agricultural, Mining, Construction- Transportation and Communication- Wholesale Trade- Retail Trade- Services- Government- Households

Other National Truck Trip Rates

988,700 Total Internal Trips- 45% LH- 33% MH- 22% HH

Major Generators: Retail, Manufacturing and Transportation


Internal Trips

Daily Two-Way Trips

LH MH HH Total %

Households 208,891 46,599 12,319 267,809 27%

Ag/Min/Con 19,760 32,201 21,917 73,878 7%

Retail 67,788 107,789 40,225 215,802 22%

Gov't 3,292 905 17,696 21,893 2%

Mfg 38,830 63,250 43,010 145,090 15%

Transp 62,392 13,957 48,191 124,540 13%

Wholesale 17,303 29,058 27,870 74,231 8%

Service 22,748 35,247 7,499 65,494 7%

All sectors 441,004 329,006 218,727 988,737 100%

% 45% 33% 22% 100%


Special Truck Trip Generators

Port of Los Angeles

Port of Long Beach

Intermodal Transfer Terminals

Air Cargo Trips at Regional Airports


Total Trip Generation

989,000 Internal

36,000 External

16,000 Port Trips

10,000 Air Cargo Trips

Inte

rnal

Ex

tern

al

Po

rt T

rip

s

Air

Car

go

Tri

ps


Trip Distribution

Gravity Model Format

Friction Factors by Weight Class

Truck Trip Diary Surveys

Based on Observed Trip Length Frequencies


External Trips Based on Commodity Flows

Southern California Goods Movement Study

County to County Movement of Goods by Tonnage

- Truckload

- Less-than Truckload

- Private Carrier

Tonnage Converted to Truck Trips by Class Outbound Based on Producing Industries

Inbound Based on Consuming Industries

Disaggregated to Regional Zones Based on 2-Digit SIC

Allocated to Regional Model Cordon Points


Time of Day Distribution

Daily Trip Generation

Distribution to Four Periods (AM, Midday, PM, Night-

time)

Weigh-In-Motion (WIM) Station Data

Factors for Internal and External Truck Trips

Factors by Weight Class


Heavy Duty Vehicle Classification Correspondence

Caltrans/FHWAClassification

SCAG ModelWt. Class

3 Light-Heavy

4567

Medium-Heavy

89

1011121314

Heavy-Heavy


Heavy Duty Truck Time Period Distribution Factors

(Percent of total daily 24-hour)

Morning Peak6 AM - 9 AM

Evening Peak3 PM - 7 PM

Mid-day9AM - 3 PM

Night7 PM - 6 AM

Light-Hvy Internal 18.69 24.27 29.84 27.20

External 17.71 26.21 32.72 23.36

Medium-Hvy Internal 17.74 21.83 37.04 23.38

External 14.65 25.10 42.64 17.61

Heavy-Hvy Internal 14.30 16.75 38.62 30.34

External 12.99 19.24 30.39 37.73


Network Development

Network Capacity Re-Adjustments

Network Coding of Significant Grades

Truck Restrictions


Traffic Assignment

Truck Assignment Integrated with Traditional AutoAssignment Process

Dynamic Two-way Interaction Between Autos and HDTDuring Assignment (Truck PCE Adjustments):

- Significant Grades

- Composition of Trucks

- Level of Congestion


HDT Traffic Assignment Process

Com posite PC E Values % G rade W t. C lass % Trucks

DAILY TRUCK O & DTRIP TABLES

PeakPeriod

Factors

F

Loaded Highway Network

Equilibrium Iterations

V/C

PCE V/CFactor

PEAK PERIODTRIP TABLES

AUTOS & TRUCKS

SIMULTANEOUS EQUILIBRIUMTRAFFIC ASSIGNMENT

L

M

H Hp

Hp

M p

M p

Lp

Lp

HOVp

HOVp

SOVp

SOVp

L= Light Heavy Trucks

M= M ed iu m H eavy Trucks

H= H eavy Heavy Trucks

Factors

Trip Tables

Assig ned Volum es


Heavy Duty Truck PCE Values by Vehicle Type,

Terrain and Percent Trucks

PercentTrucks

Lgth.inmi.

Light-Heavy % Grade

Medium-Heavy% Grade

Heavy-Heavy % Grade

0-2 3-4 >4 0-2 3-4 >4 0-2 3-4 >4

0-5<1 2.0 4.2 6.4 3.4 6.9 8.8 4.3 8.0 11.3

>1 2.0 5.5 7.5 5.2 8.4 10.7 6.7 10.5 13.5

5-10<1 2.0 3.4 4.8 3.1 5.0 6.4 3.5 5.8 8.8

>1 2.0 4.2 5.3 3.9 5.9 7.8 4.8 7.8 13.5

>10<1 2.0 3.3 4.1 2.8 4.5 6.0 3.2 5.1 8.3

>1 2.0 3.5 5.0 3.7 5.3 7.5 4.0 7.5 12.5

PercentTrucks

Lgth.inmi.

Light-Heavy % Grade

Medium-Heavy% Grade

Heavy-Heavy % Grade

0-2 3-4 >4 0-2 3-4 >4 0-2 3-4 >4

0-5<1 2.0 4.2 6.4 3.4 6.9 8.8 4.3 8.0 11.3

>1 2.0 5.5 7.5 5.2 8.4 10.7 6.7 10.5 13.5

5-10<1 2.0 3.4 4.8 3.1 5.0 6.4 3.5 5.8 8.8

>1 2.0 4.2 5.3 3.9 5.9 7.8 4.8 7.8 13.5

>10<1 2.0 3.3 4.1 2.8 4.5 6.0 3.2 5.1 8.3

>1 2.0 3.5 5.0 3.7 5.3 7.5 4.0 7.5 12.5


PCE Value Adjustment Factors for Highway

CongestionPercent Trucksin Traffic

Volume/Capacity

Light-Heavy

Medium-Heavy

Heavy-Heavy

0-5 <.5 0.6 0.7 0.9.5-1 0.8 0.8 1.2

1-1.5 1.1 1.2 1.3

1.5-2 1.0 1.2 1.2

>2 1.0 1.2 1.3

5-10 <.5 0.7 0.8 0.9.5-1 0.9 1.0 1.2

1-1.5 1.2 1.3 1.3

1.5-2 1.0 1.2 1.3

>2 1.0 1.2 1.3

>10 <.5 0.7 0.8 0.9.5-1 0.9 1.0 1.2

1-1.5 1.2 1.3 1.3

1.5-2 1.0 1.2 1.3

>2 1.0 1.2 1.3

Note: Numbers in this table are not PCE values. They are adjustmentfactors which should be applied to PCEs in previous table for each condition.


Calibration/Validation

Model Calibration at Every Step

Assignment Validation- Total 11 Regional Screenlines - 1% Variance

- Total 24 Sub-regional Screenlines - 8% Variance

- Check for Reasonableness on Arterials

(percent trucks between 4% and 7%)


Regional Model Screenlines

LOS ANGELES COUNTY

VENTURACOUNTY

Numbered ScreenlineState RouteCounty BoundryLARTS Regional Boundry

SAN BERNARDIN O COUNTY

RIVERSIDECOUNTY

ORANG ECOUNTY

1 7

2

8

3

9

4

10

5

11

6


Comparison of Truck Volumes and Counts on

Regional Model Screenlines

Screenline

CountVolume(ADT)

ModelVolume(ADT)

Difference(Model-counts)

Variance(%)

AllowanceVariance perNCHRP

1 56,055 73,355 17,300 31% +/-31%

2 105,523 113,802 8,279 8% +/- 25%

3 59,381 54,555 (4,826) -8% +/- 30%

4 65,344 58,714 (6,630) -10% +/- 29%

5 83,746 85,883 2,137 3% +/- 23%

6 73,546 72,220 (1,326) -2% +/- 28%

7 52,893 40,121 (12,772) -24% +/- 36%

8 84,401 76,090 (8,311) -10% +/- 26%

9 29,135 27,262 (1,873) -6% +/- 40%

10 16,906 22,372 5,813 34% +/- 46%

11 12,867 14,288 1,421 11% +/- 52%

Total 633,798 638,662 (4,864) 1% N/A


Subregional Corridor Screenlines

LOS ANGELES COUNTY

VENTURACOUNTY

Numbered Screenline

SAN BERNARDIN O

COUNTY

RIVERSIDECOUNTY

ORANG ECOUNTY

C

F H

L

P

T

E

D

K

O

S

X

W

J

N R

V

B

I

M

Q

U

A

G

Numbered Screenline


Comparison of Truck Volumes and Counts on Subregional

ScreenlinesScreenlineLocation,Subregion

Counts(ADT)

Model(ADT)

Difference(M - C)

Variation(%) NCHRP

A Ventura County 12,934 13,933 999 8% +/- 52%

B Ventura County 13,229 14,267 1,038 8% +/- 50%

C Ventura/LA Co. 20,531 23,225 2,694 13% +/- 43%

D N. LA Co. (I-5) 18,216 18,515 299 2% +/- 49%

E N. LA Co. 28,612 31,543 2,931 10% +/- 43%

F N. LA Co. (I-5) 30,050 32,442 2,391 8% +/- 38%

G N. LA Co. (SR 14) 3,816 3,469 (347) 10% +/- 65%

H SF Valley 39,345 35,632 (3,713) -9% +/- 40%

I SF Valley 30,352 36,249 5,897 19% +/- 35%

J Westside LA 48,827 46,052 (2,775) -6% +/- 33%

K LA County 98,568 108,750 10,182 10% +/- 22%

L LA County 101,499 99,609 (1,890) -2% +/- 21%

M SE LA County 81,171 85,277 4,160 5% +/- 27%

N E SG Valley 76,964 77,109 145 0% +/- 26%

O N. Orange County 64,745 67,142 2,397 6% +/- 28%

P S. Orange County 35,480 33,319 (2,162) -6% +/- 37%

Q N. Orange County 48,145 43,28 (4,863) -10% +/- 38%

R SB County 69,890 69,894 3 0% +/- 29%

S SB County 49,920 54,654 4,734 9% +/- 32%

T N. SB Co. (I-215) 16,742 15,280 (1,462) -9% +/- 48%

U Riverside Co. 12,129 11,026 (1,103) -9% +/- 50%

V SB County 11,469 11,319 (150) -1% +/- 49%

W Riverside County 12,438 18,162 5,724 46% +/- 49%

X N. SB County 26,488 17,799 8,689 -33% +/- 39%


Comparison of Total Vehicular Volumes and Traffic Counts on Regional Screelines

1994 Ground Counts 1994 HDT Model % Total

Screenlines Autos HDT Total Autos HDT Total Difference1 1,442,833 56,055 1,498,888 1,278,342 73,355 1,351,697 -10%

2 2,210,602 105,523 2,316,125 2,066,163 113,802 2,179,965 -6%

3 1,179,505 59,381 1,238,886 1,037,813 54,555 1,092,368 -12%

4 1,618,517 65,344 1,683,861 1,583,878 58,714 1,642,592 -2%

5 1,425,686 83,746 1,509,432 1,535,064 85,883 1,620,947 7%

6 836,320 73,546 909,866 797,356 72,220 869,576 -4%

7 617,170 52,893 670,063 656,778 40,121 696,899 4%

8 1,183,291 84,401 1,267,692 1,178,549 76,090 1,254,639 -1%

9 363,082 29,135 392,217 425,656 27,262 452,918 15%

10 379,735 16,906 396,641 391,802 22,372 414,174 4%

11 179,632 12,867 192,499 209,540 14,288 223,828 16%

Total 11,436,373 639,797 12,076,170 11,160,941 638,662 11,799,603 -2%


Products/Application Provides Missing Component to the Existing SCAG Model

Forecast of HDT on Freeways, Arterials and Ramps

Forecast of HDT by Peak Periods and Classification

Forecast of HDT Speeds, Emissions, VMT, VHT,

O/D Trip Patterns, Local vs Through Trips, Facility

Users


Comparison of 2020 and 1995 Forecast Truck Volumes on Regional Model

Screenlines

Screenline

2020Model

Volume(ADT)

1995Model Volume

(ADT)Difference

(2020-1995)Growth

(%)1 125,326 74,355 50,971 69%

2 182,951 113,802 69,149 61%

3 98,393 54,555 43,838 80%

4 64,659 58,714 5,945 10%

5 128,392 85,883 42,509 49%

6 120,182 72,220 47,962 66%

7 31,454 40,121 8,667 22%

8 169,248 76,090 93,158 122%

9 49,838 27,262 22,576 83%

10 44,681 22,719 21,962 97%

11 24,786 14,288 10,498 73%

Total 1,039,910 640,009 399,901 62%

LOS ANGELES COUNTY

VENTURACOUNTY

Numbered ScreenlineState RouteCounty BoundryLARTS Regional Boundry

SAN BERNARDIN O COUNTY

RIVERSIDECOUNTY

ORANG ECOUNTY

1 7

2

8

3

9

4

10

5

11

6


Recent Improvements

New allocations of trucks to the four time periods (AM, PM, MD, and NT), based on driver survey.

New 2000 employment SIC data from EDD

Revised PCEs

New 24-hour truck counts

Removed K-factors in the original HDT model.