The demand stratum constitutes the basic demand object for calculating trip generation, trip distribution and mode choice. It links an activity chain with one or several person groups (in the tour-based model with exactly one person group). The pointers to activity chains and person groups in the Standard 4-step model are optional.
The correlations between the various demand objects can be display graphically as follows:
Illustration 54: Correlations between different demand objects
The demand object demand stratum has the following attributes.
|
Attribute |
Description |
|
Code (Key) |
Code (any string), for example HWH Stud |
|
ActChainCode |
Activity chain code (optional) |
|
DemandGroupCodes |
Person group codes (optional) |
|
Name |
Name of demand stratum, for example student-shopping or employee+car home-shopping-home |
|
DemandModelCode |
Abbreviation of the demand model, for the respective demand stratum, for example DEFAULT |
|
Distribution matrix number |
Number of demand matrix to which the result of the distribution for this demand stratum is stored (optional) |
|
Demand time series number |
Number of demand time series for temporal distribution of demand (optional). |
The following attributes describing demand strata are only relevant for EVA models.
|
Attribute |
Description |
|
Origin structural property codes |
Origin of the structural property codes |
|
Destination structural property codes |
Destination of the structural properties codes |
|
Balancing |
Indicates the demand stratum (origin-destination type 3) in which balancing takes place |
|
Quantity as potential |
This Boolean attribute describes whether the productions or attractions of the demand stratum impact as potentials in Trip distribution/Mode choice (=1) or only have to meet the constraints (=0). |
|
Marginal totals type origin Marginal totals type destination |
Type of marginal totals of the constraint on origin or destination side |
|
Marginal totals min factor origin constant Constraints max factor origin constant Constraints min factor destination constant Marginal totals max factor destination constant |
This Boolean attribute describes, whether the lower or upper limit of the production and attraction is constant (=1) or zone-dependent (=0). |
|
Constraints min factor origin Constraints max factor origin Constraints min factor destination Constraints max factor destination |
Factor for the upper or lower limit of production or attraction. |
