Spring 2025: Michael G. Mc Nally (mmcnally-at-uci-dot-edu) [15450]
Homework 7 -- Trip Table Adjustments [Due: Wednesday 28 May 2025]
The following problems deal with a hypothetical, 4-zone region (this data was used in the prior homework assignment). Table 1 summarizes activity system and HBW trip generation data (Ps and As) for 2020, and estimates of activity system variables for 2030. Use the Table 2 base Trip Distribution in all problems.
Table 1. Base and Future HBW Trips and Demographic Data Summary
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HBW HH(i) C(i) W(i) E(j) I(i)
P(i) A(j) Households Cars Workers Empl. Inc.
Zone '20 '20 ---------- ---------- ---------- ---------- -----
'20 '30 '20 '30 '20 '30 '20 '30 both
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1 825 710 321 330 447 460 390 395 300 300 Low
2 775 800 402 470 360 420 345 480 360 450 Med
3 910 970 330 300 396 375 582 570 600 690 High
4 865 895 375 420 450 465 399 450 456 455 Med
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Tot 3375 3375 1428 1520 1653 1720 1716 1895 1716 1895 N/A
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Table 2. Base Travel Time and Trip Distribution Matrix
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From\To 1 2 3 4 From\To 1 2 3 4 P(i)
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1 5 16 13 18 1 250 125 375 75 825
2 16 7 20 12 2 100 400 50 225 775
3 13 20 2 9 3 205 60 225 420 910
4 18 12 9 3 4 155 215 320 175 865
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A(j) 710 800 970 895 3375
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Problem 5. PA to OD by Time-of-Day (10 points)
Using the base 24-hour Home-based Work (HBW) person-trip production-attraction P-A matrix in Table 2 and the conversion factors in Table 5, develop the corresponding (a) AM-peak period, (b) PM-peak period, and (c) off-peak period origin-destination O-D matrices for HBW person-trips. Note: Show sample calculations.
Table 5. Temporal Distribution of Trips by Purpose
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--- HBW -- -- HBO -- -- NHB --
Analysis Period P-A A-P P-A A-P P-A A-P
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1. AM-peak (7-9:00am) 0.30 0.00 0.06 0.02 0.04 0.04
2. PM-peak (4-7:00pm) 0.03 0.30 0.09 0.15 0.12 0.12
3. Off-peak (other) 0.17 0.20 0.33 0.33 0.34 0.34
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Problem 6. Vehicle Occupancy (5 points)
Convert the AM-peak HBW O-D matrix of person-trips (see problem 5) to vehicle trips, using Table 6 parameters. Express as an O-D matrix.
Table 6. Base Year Vehicle Occupancy by Trip Purpose
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Type Trip purpose Average Vehicle Occupancy
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1. HBW Home-based Work 1.10 persons/vehicle
2. HBO Home-based Other 1.33 persons/vehicle
3. NHB Non-home-based 1.25 persons/vehicle
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Problem 7. Identify Paths (10 points)
The following network represents the area in question, with node numbers 5 and 6 representing major network interchanges where no activities occur (these are not centroids). Links are labeled with link length (in miles). Assume for the AM-peak period average auto speeds of 30 mph.
Apply Dijkstra's Algorithm to find the minimum path tree for TAZ 1 (row 1 of the skim table). Inspect the network and apply symmetry to complete the skim table. Verify this skim table with that in Table 2. Find and tabulate predecessor nodes to identify the minimum paths for trip assignment.
Last Updated: 16 May 2025