Make it for another city

How Situ is put together, at three levels, and what another city would need

Situ is meant to be rebuilt elsewhere. The method is the same for any city; the sources are not. So the work is split in two: systems that read one city’s sources, and files that do not care which city they hold.

%%{init: {"themeVariables": {"edgeLabelBackground": "#000000", "clusterBkg": "transparent", "clusterBorder": "#3a3a3a"}, "flowchart": {"subGraphTitleMargin": {"top": 8, "bottom": 12}}}}%%
flowchart TB
  subgraph LOCAL [Different in every city]
    D[the city's own sources<br/>streets, buildings, counts, census]:::data --> S[systems S1 to S9<br/>read and test them]:::step
  end
  subgraph ANY [The same for any city]
    F[files in the published formats]:::out --> P[a game engine]:::step
  end
  S --> G[G1 World<br/>with its ledger]:::step
  G --> F
  classDef data fill:none,stroke:#8a8a8a,color:#e6e6e6
  classDef step fill:none,stroke:#8a8a8a,stroke-dasharray:4 3,color:#a6a6a6
  classDef out fill:none,stroke:#e6e6e6,stroke-width:2px,color:#ffffff
  style LOCAL fill:#000000,stroke:#3a3a3a,color:#a6a6a6
  style ANY fill:#000000,stroke:#3a3a3a,color:#a6a6a6

Three levels

Level	For someone who wants to	Start with
look	see what the systems found, street by street	the Lab, and each system’s overview (Systems)
understand	follow how a result was made, and what it assumes	each system’s “How it is built” page, its ledger and tests; Tracing a result
rebuild	make the same for another place	this page and the formats

What each system needs from a city

System	Needs	In Griffintown	Where to look elsewhere
S1 Streets	street centrelines with road classes and one-way directions	the city’s road network file, joined with its off-street paths	the city’s street file, or OpenStreetMap
S2 Scores	a segment analysis of the walking and driving networks	PlanX 4.19.0 in QGIS	the same tool on your own network
S3 Rules	stop signs, lights, banned turns, speed limits	the city’s sign, light and speed files, checked on street photos	the city’s traffic files; street photos
S4 Buildings	outlines, uses, storeys or heights	OpenStreetMap outlines; the city’s tax roll; a commercial survey; the city’s list of places	OpenStreetMap; a property or assessment roll
S5 Rhythm	counts by hour; opening hours	the city’s movement counts and bicycle detectors; opening hours in OpenStreetMap and the city’s places	the city’s counts; OpenStreetMap
S6 Streetscape	trees, lights, benches, sidewalks and other street objects	the city’s trees, hydrants, sidewalks and road works; OpenStreetMap; Mapillary	the same kinds of open files; OpenStreetMap; Mapillary
S7 Commuters	how and when residents commute; transit stops and timetables	the 2021 census (Statistics Canada); the STM’s timetable	the national census; the transit agency’s timetable
S8 Views	nothing new	worked out from S1 and S4	the same
S9 Observer	nothing new; its ledger lists what to replace	13 assumptions over S1 to S8	your own assumptions, written the same way

Two things never travel: what residents know, which needs fieldwork in each place, and the history of each place.

What is public, and what is not yet

Public: the method on every system page, the ledgers, the test reports, the run records, the result files, and the formats. Not yet public: the code. Until it is, someone rebuilding Situ can follow every rule and check every result, and writes the code themselves.