Tarmac Racer

A top-down circuit racer with real grip: brake for the corner, get the car straight, then use the throttle. 8 circuits, five modes, a ghost of your own best lap and a daily track that is the same for everybody.

ModeCircuitCarOpponents

One lap against three cars. Straight in, nothing to learn first.

How this race is scored

Driving

↑ or W accelerates, ↓ or S brakes and reverses, ← → steer. On a touch screen the four pads sit in the lower corners.
Steering tapers with speed, so a car flat out turns far less sharply than one at walking pace. Braking for a corner is a decision, not a formality.
Ask for more grip than the tyres have and the car understeers — it keeps going roughly where it was pointed and scrubs off speed. Turning in harder makes it worse, which is what makes a smooth lap a fast one.

The lap

There are 14 checkpoints round a lap and they count in order. Skipping one does not shorten the lap: the gate you skipped is still the one the game is waiting for.
A gate taken out of order costs 5 seconds, added to your time at the end.
The tarmac is 12 metres wide. Time spent off it is charged at 1.5 seconds for every second off, and the car loses grip while it is out there. A cut across the infield costs more than it saves.

The result

The field is ranked on finishing time plus penalties. A cut that won the race and cost a footnote would be a cut worth taking, so the penalty is part of the time rather than a note beside it.
A car that did not finish is placed behind every car that did, and among themselves by how far round they got.
Your best lap is kept per circuit. A race left while the tab was hidden is not recorded — the clock kept running while the cars did not, so the time would be a lie.

The opponents

Every rival drives your car, through the same physics, from the same controls. A harder opponent hits its corner speeds more precisely and wanders less; it is never given a higher top speed, more grip or a shorter braking distance.
They wander in a smooth pattern drawn at the start of the race, not at random each frame, so the same race replays the same way.

0 races, 0 laps, 0 circuit bests — all kept in this browser only.

The thing that surprises everybody

When the car will not turn, turning harder makes it worse. Past the limit of the tyres the car understeers: it keeps going roughly where it was already pointed and scrubs off speed. More lock is more understeer, not more turn.

The tyres hold a fixed sideways acceleration, so the sharpest turn a car can actually make is that grip divided by its speed. At 40 m/s a car can turn about a third as tightly as at 13 m/s. Slowing down is the only way to buy more turn — which is why braking for a corner is a decision rather than a formality.

The order that works is the one real drivers use: brake in a straight line, turn in once you are slow enough, get the car straight again, then use the throttle. A smooth lap is a fast lap here, and that is the whole game.

How to play

Pick a mode and press Start. On a keyboard the arrows or WASD drive the car — up accelerates, down brakes, left and right steer. On a phone, four pads sit in the lower corners of the track; the pedals can be swapped to the other thumb from the settings row.

The lights hold the field for three seconds. You start at the back of the grid, which is what makes one lap a race rather than a time trial with scenery.

The dashed teal line is the racing line — the fast way round, computed for that circuit rather than drawn by hand. Quick Race and the Grand Prix will show it; Time Trial, Championship and the Daily will not, because the line is the thing they are asking you to learn.

Checkpoints, laps and penalties

A lap is 14 checkpoints taken in order. Crossing one out of order costs 5 seconds and does not advance you — the gate you skipped is still the one the game is waiting for. The next checkpoint is picked out in yellow on the track.

The tarmac is 12 metres wide, and time off it is charged at 1.5 seconds for every second. It is charged by the second rather than as a flat fee on purpose: a flat fee would make one long cut cheaper than several short ones, which teaches exactly the wrong thing.

The field is ranked on finishing time plus penalties, and the penalty gets its own column on the result. A cut that won the race and cost a footnote would be a cut worth taking.

Modes

Quick Race: — one lap against three cars, straight in, with the racing line shown
3-Lap Grand Prix: — three laps and a full grid of five rivals; position is the score
Time Trial: — alone against the ghost of your own best lap, with no line to follow
Championship: — four circuits in a row with points at each, so one bad race is not the end of it
Daily Track: — one track, the same for everybody, every UTC day

Best laps are kept per circuit rather than pooled: a lap of a short, tight circuit and a lap of a long, fast one are not comparable numbers, and a single figure across all 8 would tell you that you had got worse when you had only changed track.

Tips

Brake earlier than feels necessary and get the car straight before the throttle. Almost every slow lap is a fast entry followed by a slow exit.
Watch the next checkpoint rather than the corner. It is the only thing on the track that tells you where the game thinks you are.
Two wheels on the grass costs more than the metre it saves, and it costs grip as well as seconds.
In Time Trial, the ghost is your own best lap. Where it pulls away from you is where your lap is actually going wrong — which is almost never where it feels like it is.
The three cars are genuinely different: one turns and stops better, one is faster in a straight line, one sits between them. On a tight circuit the slowest car is often the quickest.

Privacy and local play

Everything runs in your browser. Your best laps, your ghosts, your daily history and your settings are kept in this browser's local storage and are never sent anywhere — there is no account, no server and no leaderboard. The circuits are generated on your own device from fixed seeds, and the engine note is synthesised there rather than downloaded. The button under the game deletes this game's stored data and touches nothing else on Zerdly.

Frequently asked questions

Why does the car stop turning when I need it most?: Because you are asking for more grip than the tyres have. Past the limit the car understeers — it keeps going roughly where it was already pointed and scrubs off speed — and turning in harder makes it worse, not better. The fix is always the same: brake earlier, turn in later, and get the car straight before you use the throttle. The tyres hold a fixed sideways acceleration, so the sharpest turn a car can actually make is grip divided by speed; slowing down is the only way to buy more of it.
I drove through the finish line and the lap did not count. Why?: Because a lap is 14 checkpoints taken in order, not a line crossed. If you missed one, the game is still waiting for that one — so the line you just crossed was not the end of anything. This is deliberate: the start line alone would credit a lap to a car that turned round at the first corner and came back.
Does the game ever miss a checkpoint I really did cross?: No, and that is a design decision rather than a tuning one. A car at 200 km/h covers nearly a metre between frames, so a checkpoint tested by proximity — “were you within X metres of it?” — needs X to grow with speed, and any fixed value is wrong at one end. Measured over 400 laps a row, a half-metre radius misses 61% of real crossings at 140 km/h and every single one at 260 km/h. This game sweeps the segment the car travelled against the segment of the checkpoint instead: two segments either cross or they do not, which has no radius to get wrong.
Can I cut the corner across the grass?: You can drive there, and it will cost you. Time off the tarmac is charged at 1.5 seconds for every second you spend off it, and the car has far less grip out there. Checkpoints alone would not stop a cut: with only four of them the shortest legal lap on a 568 m circuit is 17.5% shorter than the racing line and strays 32 metres across the infield. Even 32 checkpoints still permit a 6.5 m excursion. Ordered gates enforce the ORDER; only the surface rule enforces the BOUNDARY, so the game has both.
Are the opponents cheating?: No, and the code makes it structural rather than a promise. Every rival drives the car you chose, through the same physics, from the same two numbers a keyboard produces — a throttle and a steer. A harder opponent hits its corner target speeds more precisely, brakes later and wanders less off the racing line. It is never given a higher top speed, more grip or a shorter braking distance, because an opponent that is faster than physically possible is not hard, it is a cheat, and you can tell within one corner.
Why is my time not recorded sometimes?: Because the tab was hidden part-way through. A hidden tab cannot run the simulation, so the race clock kept counting time the cars did not drive; the catch-up is capped so the browser does not freeze or teleport everybody three minutes down the road, and the run is marked as not recordable. Saying so out loud is the only honest option — a time with no record beside it reads as the game having lost it.
Is the Daily Track the same for everyone?: Yes. The circuit, the grid and the opponents are all seeded from the UTC date and nothing else, so two people on opposite sides of the world drive the same track on the same day. Everything else — Quick Race, Grand Prix, Time Trial — is seeded on your own device, so two races in a row are not the same race.
How is the ghost stored, and how big does it get?: As sampled positions, rotations and times — 240 samples a lap, which at racing speed is a point every few metres — rather than as a recording of your inputs. Inputs would be smaller and would also be a promise that the physics never changes; positions stay true across a version bump, because they are what you actually watched happen. Coordinates are rounded to the centimetre, and the book keeps the last two dozen circuits. The cap matters because the Daily creates a new circuit every day.
Does reduced motion change the game?: It changes the camera and nothing else. Normally the view follows your car and turns with it, which is what makes a top-down racer legible; with reduced motion on, the view holds the whole circuit still and north stays north. The rules, the physics, the timing and the scoring are identical — it is a different thing to look at, not a different thing to drive.
Why is there no leaderboard?: There is no server and no account, so there is nobody to compare you with. Your best laps, your ghosts, your daily history and your settings live in this browser and nowhere else, and the button under the game deletes all of them without touching anything else on Zerdly.