Tour-based model - Trip generation

Trip generation uses a list of group-specific activity chains which, for example, can be determined from the sample of the MiD (Mobilität in Deutschland) (BMVBS 2010) by applying a PTV optimization procedure for activity chains. For each activity chain probabilities of your daily practice have to be specified for each person group. The following table (to calculate the probabilities, these values must be divided by 100) contains examples of activity chain percentages for each person group.

 

E+c

E-c

NE+c

NE-c

Appren

Stud

SPup

PPup

Child

HWH

74.25

62.60

8.18

2.82

33.48

11.08

1.92

0.30

0.00

HBH

0.00

0.00

0.00

0.00

47.57

0.00

0.00

0.00

0.00

HOH

17.42

25.94

60.60

62.93

12.37

23.91

12.99

9.08

0.00

HRH

27.03

25.32

52.50

39.74

38.08

37.33

40.12

38.67

0.00

HGH

0.00

0.00

0.00

0.00

0.00

0.00

0.00

74.99

0.00

HUH

0.00

0.00

0.00

0.00

0.00

45.19

0.00

0.00

0.00

HSH

0.90

1.82

0.96

0.47

0.00

0.00

80.48

0.00

0.00

HWWH

3.12

0.85

0.13

0.06

0.52

0.16

0.11

0.00

0.00

HWOH

4.67

7.05

0.96

0.33

1.79

0.80

0.37

0.00

0.00

HWRH

1.64

1.46

0.18

0.02

0.86

1.56

0.09

0.00

0.00

HWSH

0.08

0.04

0.00

0.00

0.00

0.00

0.00

0.00

0.00

HBWH

0.00

0.00

0.00

0.00

0.16

0.00

0.00

0.00

0.00

HBBH

0.00

0.00

0.00

0.00

0.11

0.00

0.00

0.00

0.00

HBOH

0.00

0.00

0.00

0.00

0.97

0.00

0.00

0.00

0.00

HUROH

0.00

0.00

0.00

0.00

0.00

0.23

0.00

0.00

0.00

HURRH

0.00

0.00

0.00

0.00

0.00

0.55

0.00

0.00

0.00

HURUH

0.00

0.00

0.00

0.00

0.00

0.76

0.00

0.00

0.00

HUUOH

0.00

0.00

0.00

0.00

0.00

0.17

0.00

0.00

0.00

HUUUH

0.00

0.00

0.00

0.00

0.00

0.12

0.00

0.00

0.00

HSWWH

0.01

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

HSWOH

0.01

0.04

0.00

0.00

0.00

0.00

0.00

0.00

0.00

HSWRH

0.01

0.00

0.00

0.00

0.00

0.00

0.03

0.00

0.00

HOWOH

0.00

0.00

0.00

0.00

0.00

0.00

0.12

0.00

0.00

HSRRH

0.00

0.00

0.00

0.00

0.00

0.00

0.25

0.00

0.00

HSORH

0.00

0.00

0.00

0.03

0.00

0.00

0.14

0.00

0.00

HSOSH

0.00

0.00

0.00

0.00

0.00

0.00

0.04

0.00

0.00

HSRSH

0.00

0.00

0.00

0.01

0.00

0.00

0.17

0.00

0.00

HSRSH

0.00

0.00

0.00

0.00

0.00

0.00

0.11

0.00

0.00

HSSSH

0.00

0.00

0.00

0.00

0.00

0.00

0.03

0.00

0.00

Table 72: List of the activity chains: mobility rates per person group in %

The sum of the probabilities of a person group is often greater than 1.0 (or 100 %), because a person can complete more than one activity chains one after the other in a day (for example, person group E+c first HWH, then HRH).

The list displayed above, describes an average mobility for persons depending on the group they belong to. In the tour-based model, trip generation (i.e. determining the absolute number of activity chains and thus the trips starting from any of the individual zones) is calculated by multiplying the inhabitants of each person group with the probabilities of all activity chains. Trip generation can be limited to the active zones.

Thus, in the tour-based model, trip generation (the number of trips created with each activity in the activity chain) is determined together with the number of inhabitants and distribution of person groups. The result is saved in the zone attribute Home trips for each demand strata.

Example of trip generation with the tour-based model

2,000 employees with a car (E+c) live in zone 1. After the activity chain distribution above, run the activity chain HWOH per day with 4.67 % probability. This is why there are 2,000 • 4.67 % = 93.4 chains of the type HWOH. Consequently, home trips for the demand stratum E+c x HWOH add up to 93.4.

The 2,000 persons in this activity chain produce a total of 3 • 93.4 = 280.2 trips, namely 93.4 HW trips and just as many for WO and OH.