Built by transit lovers, for transit lovers.
There is no studio. There is no publisher. There is a person who has been reading transit project updates for fun since they were a teenager, and who got tired of games that let you draw a line anywhere and rewarded you for it.
This started as a spreadsheet. Not a metaphor — an actual spreadsheet, built to answer a question that would not go away: if you could go back and keep one of the lines that got torn up, which one should it have been? The spreadsheet grew a gravity model, and the gravity model grew a mode choice step, and at some point it stopped being a spreadsheet.
The obsession is older than that. Following a light rail extension through its environmental review the way other people follow a sports team. Knowing which corridors have been studied four times and built zero. Being able to name, off the top of your head, the year a streetcar system in a city you have never lived in was pulled up, and roughly what replaced it, and why the replacement carried a third of the riders.
Every American metro is shaped by a network somebody already built and somebody else removed.
That is the premise of the whole game, and it is why it is called Interurban. America built 15,580 miles of electric interurban railway by 1916 — briefly the largest electric railway system ever built, the only serious competitor the steam railroads had before the car — and had torn out all but 1,519 miles of it by 1950. The earliest decade you can play is the one after the last of them closed. You are the next person to try.
A debt to Streets.mn
If you want to know where the sensibility in this thing came from, a large part of the answer is Streets.mn — the Minnesota non-profit whose writers have spent years explaining, in public and for free, why a bus stop is where it is, what a zoning variance actually does, and how a corridor study turns into a road. They are why the first metro in this game is Minneapolis–Saint Paul, and why the model insists on citing itself instead of asking to be believed.
If you read nothing else after this page, read them instead of this page.
Why the model is the product
The research that started this found the same complaint under every game in the genre: the simulation was not honest. Ridership that rose because a line looked nice. Demand that appeared where you zoned it. Costs that had no relationship to what anything costs. People notice. They write reviews about it.
So the bargain here is the opposite one. The demand is real — census tracts, jobs by workplace, observed commute flows — and it is largely indifferent to you. Every coefficient is published with its source. When the model disagrees with you it shows the arithmetic, and when it cannot explain something it says so and prints the residual rather than quietly assigning it to whichever term was largest.
Sometimes that means the game tells you your beautiful line would carry eleven thousand people a day and cost two billion dollars. That is not a failure of the game. That is the game.
A tenth of it goes back
A tenth of everything this earns goes to pro-urban coalitions across the United States — transit advocacy groups, street-safety campaigns, and the land-use reform organisations doing the unglamorous work of showing up to public meetings on a Tuesday night. It would be strange to make a living arguing that transit is worth building and give nothing to the people arguing for it where it actually gets decided. Where the money went is published.
And it is disclosed
This was built with AI assistance, and that is stated here unprompted because the research found that concealing it — not using it — is what costs a game its audience: 28.6% of the negative reviews of the nearest comparable title cite undisclosed AI use. The engine is open source and the model is specified, so neither has to be taken on trust. Check it.