obtained in part (a). Discuss the differences. Which model would you prefer
for forecasting? What changes do you suggest to improve these models?
(c)
Using household size and number of vehicles in the household, develop a
cross classification model of trip generation. For each variable, justify
category definitions. Based on your model, explain how number of trips varies
with household size and number of vehicles. Compare your model with the
model developed in part (a). Which model would you use for forecasting?
Table 1-Variable Definitions. For more info visit:
http://www.transportationtomorrow.on.ca/publications.html
Variable Name
Definition
Zone
Zone number
dwtype
Dwelling unit type
n_pers
Number of Persons in the household
n_veh
Number of Vehicles in the household
n_lic
Number licenced drivers in the household
n_emf_ft
Number of fulltime workers in the household
n_emp_pt
Number of part-time workers in the
household
n_emp_home
Number of work at home persons in the
household
n_student
Number of students in the household
n_hhld_trp
Total daily trips of the household
expf
Expansion Factors
Trip Distribution
Figure 1 depicts a hypothetical 3-zone system. For each zone, projected trip
generation (in thousands of trips) in year 2041 is provided in the figure. Observed
(year 2011) morning peak-period trip matrix for this system is presented In Table 2.
Given these data, answer the following questions:
(a)
Using the biproportional algorithm, project the 2041 trip distribution matrix.
Continue the updating procedure for two iterations. Compute the error for all
rows and columns. Briefly describe the computational procedure and how
your answer is generated.
(b)
Table 3 contains travel times between zones in this system. Use the gravity
model
with
the
impedance
function
of
?
??
=
exp(−0.064
∗
𝑡𝑖𝑗)
