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Introduction to Transportation Engineering. Instructor Dr. Norman Garrick Hamed Ahangari 6 th March 2014. Trip Distribution. Gravity Model. Example 1. Calibration Factor, c = 1.5 Socio-economic factor, k ij = 1.0. Target-Year Inter-zonal Impedances, { Wij }-Given.
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Introduction to Transportation Engineering Instructor Dr. Norman Garrick Hamed Ahangari 6th March 2014
Example 1 Calibration Factor, c = 1.5 Socio-economic factor, kij= 1.0
Step 2- Find Denominator of Gravity Model Equation {AjFijKij}
AjFijKij Step 3- Find Probability that Trip i will be attracted to Zone j, {pij} pij= Σ(AjFijKij)
Step 4- Find Trip Interchanges, {Tij} Tij= Pipij
Zone 1 Zone 2 612 7 173 50 1 16 108 30 306 • Zone 4 • Zone 3 38 22
Trip Distribution Results 1000 trips 333 trips 667 trips
Example 1 Calculate the mode shares for auto and light rail transit (LRT) using the utility function given. • uk = ak – 0.045 Ta – 0.03 Tw – 0.01 Tr– 0.005 C where: Ta - access time, Tw- waiting time, Tr- riding time, C- out of pocket cost
Utility Calculations uk = ak – 0.045 Ta – 0.03 Tw – 0.01 Tr– 0.005 C
Policy AnalysisWhich 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
Scenario Analysis Congestion Pricing Increase Train Frequencies
Example 2Mode choice: Storrs to NYC • Available modes: • Auto (Private car ) • Bus • Train (From New haven) uk = ak – 0.0075 X1 – 0.012 X2 • X1: TravelCost • X2: travel Time
Scenario 2- New Utility Function(Sensitive to Out of Vehicle time) • uk = ak – 0.0075 X1 – 0.012 X2 – 0.036 X3 • X1: TravelCost,X2: in vehicle travel Time • X3:out of vehicle travel Time