You draw the roads and zone the land. Every building is designed on the spot to fit the lot it's given, and every car on the street is a resident on the way somewhere, with a parking space already booked at the other end.
Urban Sprawl is an early sandbox. There's no economy yet, and much of a city is still missing. What's here is being built from the ground up, and each piece has to work properly before the next goes on top.
A new city begins as an empty map. You lay down streets, decide what the land beside them is for, and the builders take it from there. The interesting part is what happens next: how a building makes sense of an odd-shaped lot, and whether the streets you drew can handle the people who move in.
Straight roads or curves, from quiet one-ways to four-lane streets and avenues with a painted median and left-turn pockets. Junctions, turn lanes and signal phases are worked out from what you draw, and undo is there for the intersection you'll regret. Land with no road access stays empty.
Splines · lane presets · undo and redoPick one of five housing densities, five kinds of commerce or three of industry, then paint it on: a tidy rectangle, or the awkward wedge left between two curved roads. There's no catalogue of prefab buildings. Each one is generated for its lot, with setbacks, frontage and parking considered.
13 building programs · freeform zonesBuildings go up in stages: foundations, frame, walls, finishing. Residents then keep daily routines, commuting to the offices you zoned or running an errand, and the streets go quiet at night. Speed it up, pause to look around, or bulldoze a project and pretend it never happened.
Construction · routines · day and nightNot here yet: money, a population model, city services, utilities and public transport. For now, growth follows demand targets you set yourself.
Some of these are cities built in the sandbox. Others are test scenes, set up so that buildings, lighting and traffic can be examined one at a time until they behave.
Each car belongs to a resident. It leaves home, books a parking space at its destination, drives there, and eventually heads back. In a city you start yourself, residents live in households of one to four that share a car, and they walk too: out to the car and in from it at each end of a drive, and to a nearby shop or job when that's quicker than driving, crossing at the crosswalk on every corner. Signals respond to what's actually waiting: a green ends early once its lane is empty and another direction needs it, left turns can take a gap on a flashing yellow arrow, and the walk light comes on beside the green for people waiting at the curb. Trips, parking and signal state all survive a save and reload.
Pictured: the 32-resident test neighborhood, where 16 pedestrians share four crossings. A city you start yourself begins with room for eight resident cars and grows to 16, 32 and then 64 as you build homes for them.
A recent round of work put up to 64 commuters on a single main road and sent them to work in the same morning window. A fixed-time signal, which splits every cycle the same way whoever is waiting, fell behind and never caught up. Signals that respond to waiting traffic kept pace. Here is a small version of that experiment: two identical junctions, fed exactly the same cars. Turn the traffic up, switch on the commuter rush, and watch the fixed-time queue.
25 seconds of green each way, every cycle, whoever is waiting.
Holds green while cars keep coming (up to 45 s), and gives it up once the road empties.
A simplified illustration running in your browser at four times real speed: one lane each way, no turns and no pedestrians. Delay is the extra time a car spends compared with an empty road, averaged over the last 60 cars through and every car still queued. The game's own traffic model is considerably more involved.
Most recent work has gone into traffic and the people behind it: signals that respond to what's waiting, pedestrian crossings, parking, getting vehicles through junctions without sending them into each other, and now residents who walk, cross the street and share a car. If you've seen the older version of the game, this is a ground-up rebuild; the original and its notes are in the archive.
Road editing, freeform zoning, 13 building programs, staged construction, a day and night cycle with scheduled lighting, undo and redo, and saves that remember everything, down to a car halfway into a parking space.
Residents of a new city now cross the street, at a crosswalk on every corner: beside the green at signals, where turning cars wait for them, and ahead of the cars everywhere else. They live in households of one to four people sharing one car, and one home in five keeps none. And demolishing a building no longer makes anyone vanish: people inside leave, people on the way find it closed and turn for home, and a demolished home's household moves out as each member gets back.
The multilane work left over from the avenues: lanes that end and merge in turn, turn lanes where the other lanes have to shift aside, parking along four-lane streets so homes can face them, and two-lane one-way streets. Buses come after that, then freight and rail, and the rest of the city simulation after those.
Traffic is allowed 2 milliseconds of processor time per frame. Every test scene is measured at 1×, 4× and 16× speed, and its worst-case estimate across all three has to fit. These are the current ceilings, as a share of that budget.
There's no public build and no release date. When there's something worth your time, it will be announced here first.
Back to the dev logThe screenshots show the development build. Some scenes were set up specifically to test one feature at a time.