The demand model is based on the assumption that trip purposes or external activities cause mobility. The examples given in this manual use the activities listed in the table below. They are derived from traffic surveys such as the MiD (Mobilität in Deutschland) (BMVBS 2010), whereby the activity of education has been differentiated further.
|
Work |
W |
|
Shopping |
O |
|
Education: vocational school |
B |
|
Education: university |
U |
|
Education: secondary school |
S |
|
Education: primary school |
G |
|
Recreation |
R |
|
Home |
H |
The demand object activity is described by the following attributes:
|
Attribute |
Description |
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Code (Key) |
Code (any string), for example W |
|
Name |
Name of the activity, for example housing |
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IsHomeActivity |
This Boolean attribute is true (= 1) if the activity is the starting point and end point of an activity chain. This is typically the case for the activity “Home“. |
|
DemandModelCode |
Abbreviation of the demand model the activity belongs to (any string), e.g. EVA-P. |
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Note: Activities are optional and can be defined interactively only for EVA and tour-based models. In case of Standard 4-step models one activity corresponds to exactly one activity pair. |
An activity pair corresponds to the trip between two successive activities in the daily routine of a person.
The demand object activity pair is described by the following attributes:
|
Attribute |
Description |
|
Code (Key) |
Code (any string), for example HW |
|
Name |
Name of the activity pair, for example home - work |
|
DemandModelCode |
Abbreviation of the demand model the person group belongs to (any string), for example DEFAULT. |
The following attributes describing activity pairs are only relevant for EVA models.
|
Attribute |
Description |
|
Origin activity code |
Code of the activity where the trip starts, for example H (home) |
|
Destination activity code |
Code of the activity where the trip ends, for example W (work) |
|
OD type |
Direction of the activity pair in terms of the home activity The following values are possible. 1 - Origin activity is home activity (for example home - work) 2 - Destination activity is home activity (for example shopping - home) 3 – Neither origin nor destination activity are home activity (for example others – others). By default the value of the attribute is determined by the attribute IsHomeActivity of origin and destination activity, but can also be overridden manually. It has an influence on the calculation in trip generation and trip distribution (EVA trip generation and EVA trip distribution and mode choice). |
An activity chain describes a sequence of typified activity pairs. For example, the chain home – work – shopping – home (HWOH). Such a sequence of activity pairs implies trips, in this example here three different trips (HW, WO, OH).
The following attributes describe the demand object activity chain.
|
Attribute |
Description |
|
Code (Key) |
Code (any string), for example HWH |
|
Name |
Name of the activity chain, for example home – work – home |
|
Activity codes |
Comma-separated list of activity codes |
|
DemandModelCode |
Abbreviation of the demand model the person group belongs to (any string), for example DEFAULT. |
In the tour-based demand model, the average mobility program of persons is described by activity chains. The Standard 4-step model and the EVA model allow single-element activity chains only. So an activity chain corresponds directly, i.e. 1:1, to the activity pair.
