Signal Master

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Everyone
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Everyone
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About this app

You control the lights. The city has to keep moving.

Signal Master is a puzzle game built on a real queueing simulation. Every junction has four approaches, each with its own rate of arriving traffic, and one thing under your control: how many seconds of green each approach gets before the cycle moves on.

Get the split right and the queues melt away. Get it wrong and one arm backs up while another sits empty on green.

IT IS ACTUALLY SIMULATED

Cars arrive on each approach at its own rate. A green discharges the queue at roughly 1,800 vehicles an hour, which is what a real lane manages. Two seconds of amber sit between every phase, and those seconds are gone from the cycle whether you use them or not.

That last detail is the whole game. Short greens mean more clearance overhead. Long greens mean the other three arms wait. Somewhere in between is the answer, and it is different at every junction.

WHAT YOU SEE IS WHAT IS SCORED

The junction is drawn from above with the actual queue on each arm, the running phase, the amber clearance and a live count of vehicles waiting. Nothing on screen is decoration - the cars you can see are the cars in the model.

Adjust any approach mid-shift in five second steps, or hit Skip Phase to cut a green short when an arm has emptied.

FORTY-FIVE JUNCTIONS, FIVE DISTRICTS

- Riverside - quiet streets, room for error, learn how a cycle works
- Downtown - four busy approaches and no slack anywhere
- Old Town - narrow lanes that punish long greens
- Industrial - one dominant flow and heavy vehicles
- Ring Road - the whole city funnels through, at the highest targets in the game

Traffic on one arm nearly doubles during the middle third of every shift, so a split that looked perfect at the start will need a second look.

RATED THE WAY A TRAFFIC ENGINEER WOULD

One star for hitting the junction's clearance target. Two for beating it comfortably. Three for beating it while keeping the longest queue short. The summary shows cars passed, the worst queue you allowed, the percentage cleared and the average wait per vehicle.

WHAT IS INSIDE

- 45 junctions with stars, best efficiency and best throughput recorded
- A daily challenge built from the date, the same junction for everyone that day
- Road schemes: six junction behaviours that unlock as you earn stars
- Twelve achievements and a perfect-shift streak
- Full statistics by district
- Optional queue counters, haptics and an animated sky

NO ADS MID-SHIFT, NO ACCOUNT, NO INTERNET

Everything runs on the device. Play a shift on the train and the city never notices.

Keep the city moving.
Time the lights, split the green, and keep the whole junction moving.
Updated on
Sep 6, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
  • No data shared with third parties
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  • No data collected
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Content rating
Everyone
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App support

About the developer
WYDAWNICTWO NAUKOWE IVG SP Z O O
patrykszymczak117@gmail.com
Ul. Grzybowska 80/82-700 00-844 Warszawa Poland
+380 99 129 3607