1.12: what is a good way to convert population and demand factors into pax?

[adlet]

Thinking about how to understand what the number of passengers is expected to be. Let's say simply, station A has 100,000 people in its area. Let's say there is station B which also has 100,000 people and is located exactly 10 km away. Let's say it's 8 in the morning, the distance factor for 10 km is set to be 80%, station A origin factor is 100% and station B destination factor is 100% for this time of the day.

How many passengers will be generated to go from A to B in an hour? Wondering if anyone may have done testing.

... Just did a test. Built an isolated line, two stations, 10 km apart. Set up POIs with at each station (station areas themselves were set to minimal non-zero, about 1,000 at each). Set global demand to 100%, used custom demand curves with 100% throughout the week. One train operated the line, with departures every 60 minutes.

Results- numbers are rounded

Both POI at 100,000 - 20 pax in each direction per hour
One POI at 100,000 and the other at 200,000 - 40 pax in each direction per hour
Both POI at 200,000 - 80 pax in each direction per hour
One POI at 1,000,000 and the other at 100,000 - 200 pax in each direction per hour
One POI at 800,000 and the other at 300,000 - 400 pax in each direction per hour
One POI at 1,000,000 and the other at 500,000 - 620 pax in each direction per hour
Both POI at 750,000 - 650 pax in each direction per hour
Both POI at 1,000,000 - 1,000+ pax in each direction per hour

Preliminary observations. Note I am effectively using just two geographical points here (two tiles) and not a map of multiple tiles as a real map would be.

1. Pax volume in each direction is indifferent to how big one place and how small the other. This allows to simulate return trips over the course of a day.
2. Pax volume seems to be varying with to the combined population of each of the two points.
3. When two places are similar in size, the pax traffic is higher than when one place is a lot larger than the other (but the combined population is the same).
4. Don't know if this is close to the actual formula, but if the two points have population of X and Y, and generate a demand of D passengers in each direction per hour, then if you apply a factor of a to X and a factor of b to Y (so the new populations are aX and bY), the resulting demand will be abD, subject to decay at larger volumes. I have not tested this extensively though, so could be very wrong. I also have not tested at small volume (e.g. 10,000 population).

[TKR]

you cannot simplify the current situation into a formula. Pax will want to travel to places where you don't have a station either. Their destination is based on the population layer or POIs, not your stations.

[adlet]

I think in 1.12 lack of stations in other places does not impact the demand between two given stations, if I understand what WaW wrote in his blog. Yes of course in a real map the destination is based on the population layer. This is why in my test I set up a station with the smallest possible non-zero radius (which had ~1000 people in it) and set up a POI in this narrow area that had a large population (100,000 or more). The demand was changing very quickly when I was changing the number of people in the POI, so I want to say most of the demand was driven by the size of the POI.

What I am trying to do is see how large of a POI I need to be setting in a real map to create a desired passenger effect, and also see if I can create morning/evening flows into some stations and out of others. For example, a real station has a reported real life data of 50,000 incoming paseengers per day average. Say in 1.12 this station generates 10,000 passengers. Say the networks are the same. If this is not a global setting issue, what size POI do I want to add?

For morning/evening, looks like one potential way to do it is to suppress the real population layer (minimal station bubble) and effectively place a POI next to the station with a custom demand curve.