I Love Traffic

I Love Traffic. No, I don't really, that's the name of this fast and fun little game.

Introduction
You have to prevent car crashes by changing the traffic lights from red to green or from green to red in an unknown highway which is full of cars for some reason.

Vehicle speeds
Here you'll see how fast each car accelerates and how fast it goes. 1 is lowest. (Spe: is speed and Acc: is acceleration)
Car: Spe: 2 -- Acc: 2
Motorbike: Spe: 3 -- Acc: 4
Police car and ambulance: Spe: 4 -- Acc: 4
Truck: Spe: 1 -- Acc: 1
Bus: Spe: 1 -- Acc: 1

Review
I liked this game a lot, it's kind of random, but it's fun.
The sound is quite good, I really like the music. It's the perfect song for such a game, 0.8.
The difficulty is easy, quite easy. The 20 levels are easy to beat in less than 10 minutes, but it has some hard levels which make it fair, 0.7.
I really liked this game's graphics. Very well elaborated and the vehicles are drawn nicely, 0.8.
Its gameplay is good. It's fun to play this game and relaxing too, the music makes it better, 1.
I think that this game's controls are simple, that's why they're good. Clicking games are always good because of it, 0.9.
That brings this game's total up to 4.1 / 5, which makes it another great game.

Walkthrough
Thanks again, Tass, for a walkthrough. It's a walkthrough to all levels in this game.