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Introduction to Transportation Engineering Instructor Dr. Norman Garrick Hamed Ahangari 6th March 2014

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Trip Distribution

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Gravity Model

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Example 1 P=800 A= 10 P=1500 A= 10 P=200 A= 20 P=1200 A= 2 Zone 1Zone 2 Zone 4Zone 3 Calibration Factor, c = 1.5Socio-economic factor, k ij = 1.0

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Target-Year Inter-zonal Impedances, {Wij}-Given TAZ

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Step 1- Calculate Friction Factors, {Fij} TAZ

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Step 2- Find Denominator of Gravity Model Equation {AjFijKij} TAZ1234Total Σ(A j F ij K ij )

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Step 3- Find Probability that Trip i will be attracted to Zone j, {pij} Σ(A j F ij K ij ) p ij = A j F ij K ij TAZ1234Total

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Step 4- Find Trip Interchanges, {Tij} TAZ1234Total T ij = P i p ij

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Zone 1 Zone 2 Zone 3 Zone

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Example 2 UConn. UConn Buckland Hill Westfarm Mall Eastbrook Mall

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Uconn. P1=2000 Eastbrook A1: 10 t1: 10 min Buckland Hill A2: 60 t2: 20 min Westfarm A3: 80 t3: 40 min Calibration Factor c = 2.0 Socioeconomic Adj. Factor K = 1.0

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Calculations-1 JAjt1jF1j=tij^(-2)Aj*F1j 110 1/100= /400= /1600= Total 0.30

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Calculations-2 JAj*F1jP1j= Aj*F1j/(Aj*F1j)T1j= P1*p1j /0.30= *0.33= /0.3= *0.5= /0.3= *0.167=333 Total

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Trip Distribution Results UConn Buckland Hill Westfarm Mall Eastbrook Mall 1000 trips 333 trips 667 trips

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Mode Choice

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Example 1 Calculate the mode shares for auto and light rail transit (LRT) using the utility function given. u k = a k – T a – 0.03 T w – 0.01 T r – C where: T a - access time, T w - waiting time, T r - riding time, C - out of pocket cost

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Modes Specifications Modea(k)Ta Access time Tw Waiting time Tr Riding time C Out of pocket cost LRT Auto

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Key formulas

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Utility Calculations ModeCalculationsUtility LRT = * * * * Auto = * *0 -.01* * u k = a k – T a – 0.03 T w – 0.01 T r – C

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Mode choice Estimation ModeUke^(Uk)Probability of selecting LRT Auto Total

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Policy Analysis Which policy may promote transit? 1-Applying congestion pricing for Auto mode ( Increase the cost of auto to 120) 2- Improving transit by decreasing waiting time to 5 minute

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Scenario Analysis Mode Uke^(Uk) Prob. of selecting LRT Auto Total Mode Uke^(Uk) Prob. of selecting LRT Auto Total Congestion PricingIncrease Train Frequencies

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Comparing Results

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Example 2 Mode choice: Storrs to NYC Available modes: Auto (Private car ) Bus Train (From New haven) u k = a k – X 1 – X 2 X1 : Travel Cost X2: travel Time

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Mode Characteristics - Auto Cost Analysis Gasoline Cost (300 miles round trip) 35 $ Tool Cost15 $ Parking Cost40 $ Total Cost80 $ Time Analysis Round trip150*2=300 min Parking20 Total time320 min

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Mode Characteristics - Bus Cost Analysis Ticket Cost Round trip 25*2= 50 $ Time Analysis Waiting time15*2= 30 min Round trip Travel time210*2=420 Total time440 min

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Mode Characteristics - Train Cost Analysis Gasoline Price12 $ Parking8 $ Train Ticket27 $ Total Cost47 $ Time Analysis Driving from Storrs to New Haven55*2=110 min Parking20 min Transfer time2*15= 30 min Train from New Haven to NYC100*2=200 min Total time360 min

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Modes Characteristics ModeTotal CostTotal Timea(k) Auto Bus Train

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Utility Calculations ModeCalculationsUtility Auto= * * Bus= * * Train= * *

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Mode choice Estimation ModeUke^(Uk)Probability of selecting Auto Bus Train Total

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Scenario 2- New Utility Function (Sensitive to Out of Vehicle time) u k = a k – X 1 – X 2 – X 3 X1 : Travel Cost,X2: in vehicle travel Time X3:out of vehicle travel Time

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Modal Choice in Scenario 2 ModeUke^(Uk)Probability of selecting Auto Bus Train Total

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