u/Grenagar

Buildings appear by themselves as the city grows. Your job is everything that moves: roads, traffic lights, multi-level interchanges, bus lines with dedicated lanes, trains, and metro underground.

Every car drives itself - keeps its lane, changes lanes, waits at lights, reroutes around jams - 10,000+ of them at once on maps up to 18x18 km. Jams happen for real reasons: a bad merge, a short ramp, one badly-timed light. Finding the junction that's ruining your city (heat maps and 20+ live charts help) and fixing it is the whole game.

The style is minimalist - Mini Metro and Mini Motorways were the inspiration - but in 3D, because you can't build a proper cloverleaf in 2D.

There's also a challenge mode (8 interchange puzzles - build a junction, traffic stress-tests it), a Creative mode with unlimited money, and a map editor.

The browser version reached 150,000+ players. The Steam version is the full game - bigger maps, more cars, all the transit.

Hey r/CityBuilders! Some of you have followed Traffic Architect since I posted the first version here about 5 months ago - a traffic management game I've been building solo, free in the browser. Since then it's passed 140k+ plays with a 9.2 rating on CrazyGames, and the most common request by far was "put it on Steam." So - the Steam page went live today:

https://store.steampowered.com/app/5028050/Traffic\_Architect/

The Steam version isn't a port, it's a big expansion of the game:

- Much bigger maps - up to 18×18 km (the whole web map is 6×6)

- Highways and multi-level interchanges

- Public transport (revealing details over the coming weeks - it's the biggest thing I've built)

- Congestion heat-map, turn restrictions, smarter traffic light control

- Map editor with Steam Workshop support

- Full stats - 20+ live charts tracking your city

The web version stays free.

If you enjoyed the game or the posts here, a wishlist genuinely helps a solo dev more than anything else right now.

Happy to answer anything about the game or what's coming and thank you for previous feedback!

A few months ago I posted my road network builder here and got a lot of great suggestions. Big update on what's been added since:

Traffic Lights:

Unlocks at Stage 3. Place them on any intersection, configure phase groups - opposite directions get green together. Adjust each phase from 5s to 120s. Left turns on green yield to opposing traffic. A busy intersection you've outgrown can now be managed instead of rebuilt.

Freight Tiers:

Deliveries now scale with your city. Small houses spawn only regular cars. Medium buildings mix in cargo trucks (~30%). Big buildings are full logistics hubs - cars, cargo trucks, and 16m articulated semi-trailers, twice the length of a truck. Semis route intelligently: they only deliver between medium and big buildings, pay the most per delivery, take two slots in the building's queue, and obey a slower heavy-vehicle speed limit. Net effect: ~20% fewer vehicles for the same income, so big-building districts feel like proper industrial zones instead of a wall of identical cars. Planning truck-friendly corridors between your industrial districts is now part of the expansion puzzle.

Roundabout Improvements:

Snap-to-roundabout - hover any existing intersection and it previews a ring sized to fit. Click to fine-tune radius, click again to commit. Old approach roads get trimmed and joined automatically. No more demolish-and-rebuild to convert a busy junction - this was one of the most requested changes for the "redesign a messy intersection" moment.

Smarter Drivers:

Cars avoid entering an intersection unless their exit is actually clear (don't-block-the-box), hold at the stop line when merging into a blocked lane, and no longer deadlock in yield cycles at busy junctions. Congestion now comes from genuinely undersized infrastructure, not AI silliness.

Creative Mode:

No game-over, unlimited money, hand-place buildings yourself. Pick which plots to unlock, choose from small/medium/big buildings. Pure layout and traffic-flow sandbox for people who want to build without the economy pressure.

Performance:

Big optimization pass - adaptive simulation LOD, render interpolation, car culling. Up to 10,000 cars now run smoothly, so late-game megacities stay playable. Saves also got ~25% smaller.

Smaller stuff: rocks as a new terrain obstacle (compact clusters, pricier to clear than trees), smarter traffic recalculation so cars find new shortcuts right after you build or upgrade roads, Ctrl locks snapping to same elevation (no more accidentally connecting ground roads to bridges), cinematic mode (M hides the HUD, J chases any car), more varied building colors and ground clutter.

Free in browser and mobile: https://www.crazygames.com/game/traffic-architect-tic

The progression and expansion feedback from this sub last time helped a lot - would love to hear what you'd want next. And still have many improvements and updates planned!

Last time I posted about traffic lights, roundabouts and creative mode. Here's what's new since then:

Freight now comes in two tiers. Small houses spawn only regular cars. Medium buildings mix in cargo trucks (~30%). Big buildings are full logistics hubs - cars, cargo trucks, and now 16m articulated semi-trailers, twice the length of a truck. Trailers route intelligently: they only deliver between medium and big buildings - you'll never see a semi trying to squeeze up to a small house. They pay the most per delivery, take two slots in the building's queue, and share the slower heavy-vehicle speed limit. Net effect: ~20% fewer vehicles on your roads for the same income, so big-building districts feel like proper industrial zones instead of a wall of identical cars.

Smarter Drivers - cars now avoid entering an intersection unless their exit is actually clear (don't-block-the-box), hold at the stop line when merging into a blocked lane, and no longer deadlock in yield cycles at busy junctions.

Big optimization pass - adaptive simulation LOD, render interpolation, car culling, shadow caching. Up to 10,000 cars now run smoothly. Saves also got ~25% smaller.

Smaller QoL improvements:

- Cinematic mode - photo mode (M) hides the HUD, follow camera (J) chases any car

- More varied building colors, ground clutter (crops, flowers, bushes, shore debris)

- UI improvements

Free in browser and mobile: https://www.crazygames.com/game/traffic-architect-tic . Many other improvements planned!

Traffic Architect - got a lot of great suggestions from this community last time. Here's what's been added:

- Traffic Lights

Unlocks at Stage 3. Place them on any intersection, configure phase groups - opposite directions get green together. Adjust each phase from 5s to 120s. Left turns on green yield to opposing traffic. Cars stopped at red no longer honk at the car in front.

- Roundabout Improvements

Snap-to-roundabout - hover any existing intersection and it previews a ring sized to fit. Click to fine-tune radius, click again to commit. Old approach roads get trimmed and joined automatically. No more demolish-and-rebuild to convert a busy junction. Also added rotation control - drag to set radius and aim where the first junction sits.

- Creative Mode

No game-over, unlimited money, hand-place buildings yourself. Pick which plots to unlock, choose from small/medium/big buildings. Focus purely on layout, traffic flow, and aesthetics.

Other improvements:

- Rocks - new terrain obstacle, compact clusters that cost more to remove than trees

- Smarter traffic recalculation - cars find new shortcuts after you build or upgrade roads

- Improved mountain visuals

- Smarter road snapping based on actual road width

- Ctrl now locks snapping to same elevation - no more accidentally connecting ground roads to bridges

Free in browser and mobile: https://www.crazygames.com/game/traffic-architect-tic

What else would you want to see added?