UP 431: Urban Transportation Modeling Spring 2021
Assignment 4: Estimating Travel Demand
Due date: April 15
In this assignment, you will estimate the travel demand for the 10-TAZ area depicted in Figure 1.
Your output for each step will feed into the next. Supplementary information you’ll need is
provided below, as a separate data file on Compass, or in Appendix F of the CUUATS 2040
Long Range Transportation Plan.
Submit a single Excel file where each tab is the result of one of the steps, found in questions 1-3
below. The more work you show in the Excel workbook, the more likely you are to receive
partial credit. But, make it clear and obvious where we should find the final output to each step.
Tip: it will be helpful to import all data files into your assignment excel file as worksheets before

Figure 1: 10-TAZ area in Champaign

UP 431: Urban Transportation Modeling Spring 2021
1. Trip Generation: Calculate the number of trip productions, trip attractions, and balanced
attractions for each trip type (HBW, HBSc, HBSh, HBO, NHB) for each zone in the map.
Use the trip production and attraction rates for urbanized TAZs found in tables F.9 and
F.10 in Appendix F. (Use the special generator formula on p. 637 for HBSc trips.) The
demographic and employment data needed is available on Compass. Trip control totals
are in Table 1.

2. Trip Distribution: Using the production and attraction matrices derived in question 1,
calculate the trip distribution for this sub area. Use the friction factors found in Table
F.19 in Appendix F. Use the time and distance matrices provided on Compass to
calculate travel impedance (Generalized cost), using the formula in Appendix F (p. 640).
Balance trip origins and destinations to under 5% error. Note that friction factors are not a
function of travel time here, but generalized cost. Tip: use “VLOOKUP” or
“XLOOKUP” function in excel to find a friction factor that correspond to a given
generalized cost. Tip2: don’t be surprised by similar generalized costs and friction factors
across the cells! This is because all 10 TAZs are clusters at the central location of
Champaign.

3. Mode Choice: Calculate the share of trips for each of the five modes in the mode choice
model (Drive Alone, Share Ride, Transit, Bike, and Walk). Calculate shares for only
HBW, HBSh, and HBO trips. Use the mode choice coefficients in Table F.24 and travel
costs in Table F.22 in Appendix F. Assume a bicycling speed of 10 mph and a walking
speed of 3 mph. Use the transit times found in the file on Compass. (Note: For intrazonal
transit trips, assume wait time is the minimum wait time, in-vehicle time is half the
minimum in-vehicle time, walk access time is the minimum walk access time, and
transfer wait time is zero. Minimum in this case means the non-zero minimum.) Also
note that cost of travel is not included in the mode choice function.

4. Trip Assignment: It’s not possible to calculate trip assignment in this subarea because
the one-way streets limit the possibilities too much. No answer due for trip assignment!
Table 1: Trip Control Totals
Productions Attractions
HBW HBSc HBSh HBO NHB HBW HBSc HBSh HBO NHB
Internal 115,449 154,782 89,626 246,089 217,133 133,003 159,955 103,635 280,869 256,461
External 37,832 0 6,853 31,569 8,725 11,298 0 9,075 6,926 14,461
Total 153,281 154,782 96,479 277,658 225,858 144,301 159,955 112,710 287,795 270,922  