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Provisional Estimates of FAF O-D Freight Flows by Highway. Charlie Han MacroSys Research and Technology May 15, 2007. Objective. Develop Provisional Estimates of FAF Origin-Destination Freight Flows by Highway Measurements: Tons and Value ($) Commodity Detail: 2-digit SCTG level
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Provisional Estimates of FAF O-D Freight Flows by Highway Charlie Han MacroSys Research and Technology May 15, 2007
Objective Develop Provisional Estimates of FAF Origin-Destination Freight Flows by Highway • Measurements: Tons and Value ($) • Commodity Detail: 2-digit SCTG level • Types of Origins and Destinations • Domestic: FAF Regions • International: FAF Regions and Ports of Entry/Exit
An “updating” approach Growth in freight tonnage Provisional estimate of new freight tonnage Benchmark Year freight tonnage Freight flow from one region to another
What do we want? Answer: Freight flows by commodity and by FAF O-D regions FAF Region B Commodity flows A C
National total with commodity details Method for Domestic O-D Flows Estimation Steps: Step 1: The growth in total domestic highway freight tonnage National total without region and commodity details = Total domestic highway freight tonnage of benchmark year × Growth rate of highway freight calculated from ATA’s trucking tonnage index Step 2: Break total growth into growth by commodity Growth by commodity = Total growth × Shares of commodities in Total Output ($)
Method for Domestic O-D Flows Estimation Steps: Step 3: Distributing national growth by commodity to FAF regions For Example:X(B-C) = X × DF(X, B-C) ▲ National tonnage of commodity X (▲X) Distribution Factor (DF) B ▲ Regional flow of commodity X (▲X, B-C) A C
Method for Domestic O-D Flows Estimation Steps: Step 3-1: Calculating distribution factor for each pair of FAF O-D regions and each commodity Y(B-C) = (GDP(B) +GDP(C)) / (GDP(B, 0) +GDP(C, 0)) × X(B-C, 0) DF(X, B-C) = Y(B-C) / (Y(A-B),Y(A-C), ……, Y(B-C) ) And, (DF(X, A-B),DF(X, A-C), ……, DF(X, B-C) ) = 1 ▲GDP B Commodity X in Benchmark year (X, O-D) GDP B Growth in GDP $ B ▲GDP A ▲GDP C A GDP A GDP C C Economic Size in Benchmark year
Method for Domestic O-D Flows Estimation Steps: Step 4: Calculating provisional tonnage estimates Provisional Tonnage Estimate: X(B-C, t) = X( B-C, 0) + X(B-C) ▲ National tonnage of commodity X (▲X) ▲ Regional flow of commodity X (▲X, B-C) Distribution Factor (DF) B Regional flow of commodity X in benchmark year (X, B-C) A C
Method for International O-D Flows I(A) + I(B) + I(C) = I(P1) + I(P2) + I(P3) + I(P4) E(A) + E(B) + E(C) = E(P1) + E(P2) + E(P3) + E(P4) Imports Exports Imports Exports Imports Exports Imports Exports ? Port 2 Port 3 Port 1 ? E (AP1) ? Imports Exports Port 4 I (P1A) ? Imports Exports Imports Exports B A C
Method for International O-D Flows E(X, AP1, t) = E(X, A, t)× S(P1, X, A, 0) Where, S(P1, X, A, 0) = E(X, AP1, 0)/ E(X, A, 0) S(P1, X, A, 0) + S(P2, X, A, 0) + S(P3, X, A, 0) + ……+ S(Pn, X, A, 0) = 1 For Commodity not in FAF benchmark year (0): E(X, AP1, t) = E(X, A, t)× S(P1, A, 0) Where, S(P1, A, 0) = E(AP1, 0)/ E(A, 0) S(P1, A, 0) + S(P2, A, 0) + S(P3, A, 0) + ……+ S(Pn, A, 0) = 1 ? If [(E(X, AP1, t), E(X, BP1, t), E(X, CP1, t) ), for all X] = E(P1, t) If not: E(P1)=[(E(X, AP1, t), E(X, BP1, t), E(X, CP1, t)), for all X] - E(P1, t)
Method for International O-D Flows For Port i, where E(Pi) > 0, R(Pi) = E(Pi, t) / [(E(X, AP1, t),E(X, BP1, t),E(X, CP1, t)), for all X] E'(X, APi, t) = R(Pi) × E(X, APi, t) , WhereR(Pi) < 1 Then, [( E'(X, APi, t), E'(X, BPi, t), E'(X, CPi, t)), for all X] = E(Pi, t) Since E(A) + E(B) + E(C) = E(P1) + E(P2) + E(P3) + E(P4) (E(P1), E(P2), E(P3), E(P4) )= 0 For Port j, where E(Pj) < 0, U(Pj) = E(Pj) / (E(Pj), for all j) E'(X, APj, t) =E(X, APj, t) + U(Pj)×[(1-R(Pi))×E(X, APi, t), for all i)] Then, [( E'(X, APj, t), E'(X, BPj, t), E'(X, CPj, t)), for all X] = E(Pj, t)