I wonder if someone can provide me with a sample of a simple trip generation model containing the script within it. I want to learn the steps and the way trip generation script is written with regression equations.
Thanks a million in advance!
Hello. Please have a look at the simple trip generation example contained within the CUBETOWN Demonstration Model available for download here:
https://communities.bentley.com/products/citilabs-cube/w/cube-streetlytics-wiki/51411/cubetown-demonstration-model
Chapter 11 of the CUBE Voyager Reference Guide provides explanation of the syntax: "Generation Program".
Answer Verified By: Farhad Ahmadzai
The sixth trip purpose in generation step of CUBETOWN Demonstration Model seems mistaken, i.e. the trips in the ILOOP are scripted as production, consequently, the sixth trip purpose must be Internal-to-External not External-to-Internal.
Hello. Thanks for your observation. In this simplified demo model, P[6] is defined from the input zonal file attribute: zi.2.EITRIPS = External-Internal. These are "productions" for the external zones TAZ=17,18,19,23,24,25. Please have a look at the output table from the Generation step, where you can see those "productions" for the external zones.
EI and IE trip tables will be generated from the PA and AP matrices with PA and AP weights inside the assignment step.
If I have a zonal file that does not have headings, how would I be able to index the columns in production and attraction calculations? For example, zonal file 1 column3. I have indexed it as ZI.1.3 but it appears to be an error.
As far as EI is concerned, these trips can only be called "productions" that originate outside of the model area and end at the TAZ zones. I still firmly believe that technically these trips should be called IE (Internal to External).