Green Wave

A seeded rush-hour wave of cars pours onto a grid of intersections. You can't widen roads or add lanes, you only set each traffic light's green split (how long each direction gets) and its offset (when its green starts). Get the offsets right and a platoon of cars rolls through several intersections without stopping: a green wave. Get them wrong and queues back up until a car is stranded inside an intersection, blocking the cross traffic, a blocked box, which spreads into full gridlock and ends the run.

• Set each intersection's green split between its two directions
• Stagger the offsets so a moving platoon keeps hitting greens
• Clear as many cars as possible during the rush
• Keep queues from backing up through an intersection (a blocked box)
• Avoid gridlock, too many blocked boxes ends the run

• Tap or click an intersection to select it, then adjust its green split and offset
• Use the quick 'green-wave a row / column' buttons to coordinate a corridor
• Watch the grid update live as your timing changes the flow
• Works with mouse or touch on desktop, tablet and phone

• Daily, everyone gets the same seeded rush each day; compete on the daily board
• Practice, a fresh random rush every run for unlimited play

• Think in platoons: offset each downstream light so cars arrive just as it turns green
• Give the busier direction a longer green, an even split wastes capacity
• Watch for a queue that reaches back into the previous intersection; that's a blocked box forming
• A coordinated corridor clears far more cars than every light timed the same
• Relieve a jam early, once boxes block in a loop, the gridlock cascades

Green Wave is built on a real idea in traffic engineering: the 'green wave', where signals along a corridor are offset in time so a platoon of vehicles travelling at the right speed meets a run of green lights and never has to stop. Real cities tune signal timing, split and offset, to move more traffic through the same roads, and fight the 'blocked box' gridlock that happens when cars stop inside an intersection. This game turns that timing craft into a fast, deterministic daily puzzle.

Green Wave is an original, free browser simulation game with no download and no sign-up. It is a game, not a traffic-engineering tool; the city is simplified for fun. Play the shared Daily rush to climb the leaderboard, or jump into Practice for endless runs.

A free, original browser game on PlayPendium. No download, no install.