Question

Question 2: The origin-destination (O-D) trips for a three-zone system were predicted using a trip distribution model as shown below. O-D Trip Table (Person trips) Destination zone Origin zone 22 32 le 2120 233e 18312 2e 263e 4825 32272 32 229 358 1293 Assume that person trips are made by two modes - automobile and transit. Interzonal and intrazonal travel times by these two modes are shown below: Auto Travel Time (min) Destination zone Origin zone 2e le 2.4 11.02 8.2 2 11.00 2.1 7.42 3e 8.2 7.42 3.4 e Origin zone 1 2 32 Transit Travel Time (min) Destination zone 3e 8.12 22.8e 15.02 22.82 8.2 13.42 15.00 13.4 7.52 The utility functions for trips from zone į to zone j were calibrated as follows: Va = 1.2 -0.06 * (ta V = -0.06 * (tu) where V2 V = observable utilities for auto and transit, respectively: (tu) (to) = the travel times from zone i to zone j for auto and transit (minutes), respectively. (a) Calculate the O-D person trips by auto and transit separately. (b) Calculate the O-D vehicle trips by auto. Assume that the average vehicle occupancy is 1.29 persons per auto. Note: You may use EXCEL for the calculation but please show your sample calculation for one zone pair

Answer 1

Given,

Auto Travel Time (min) Destination Zone Origin Zone 1 2 O-D Trip Table (Person Trips) Destination Zone Origin 1 2 3 Zone 1 2120 233 1831 2 263 4825 3227 3 229 358 1293 3 1 2.4 11 8.2 2 11 2.1 7.4 3.4 3 8.2 7.4 Transit Travel Time (min) Destination Zone Origin 1 2 3 Zone 1 8.1 22.8 15 22.8 8.2 13.4 3 15 13.4 7.5 ئا ئنا

Given, Utility function for Auto, Va = 1.2 -0.06*(tija Utility function for Transit, V = -0.06*(tj) Sample Calculation for OD Pair 1-1 (a) No. of person trips, T = 2120 Travel time for auto from Zone-1 to Zone-1, (t11)a = 2.4 Travel time for transit from Zone-1 to Zone-1, (011)t = 8.1 Therefore, Va = 1.2-0.06*2.4 = 1.056 Vi = -0.06 * 8.1 = -0.486 OD person trips by auto (ان ها) - eva elatert *T e 1.056 11 * 2120 21.056+e-0 -0.486 = 1746.36

OD O person trips by transit = leve eva) *T e-0.486 * 2120 e 1.056+e-0.486 = 373.64 (b) Given, average vehicle occupancy for auto = 1.29 No. of vehicle trips for auto for OD pair 1-1 = (OD person trips for 1-1)/1.29 = 1746.36/ 1.29 = 1353.77 vehicle trips

Applying above methods for all OD pairs, we get

(a)

O-D Persons Trips by Auto Destination Zone Origin 1 2 3 Zone 1746.36 202.90 1525.47 2 229.02 3991.30 2666.64 3 190.79 295.83 1046.53 O-D Persons Trips by Transit Destination Zone Origin 1 2 3 Zone 1 373.64 30.10 305.53 2 33.98 833.70 560.36 3 38.21 62.17 246.47

(b)

O-D Vehicle Trips by Auto Destination Zone Origin 1 2 3 Zone 1 1353.77 157.28 1182.53 177.53 3094.03 2067.16 3 147.90 229.33 811.26 N Rounding off the vehicle numbers, we get O-D Vehicle Trips by Auto Destination Zone Origin 1 2 3 Zone 1 1354 157 1183 178 3094 2067 N 3 8 148 229 811