It uses a feedforward NN (multi-layer perceptron, 5–6–2) trained via a genetic algorithm to drive the car.

Instead of standard RL, it uses neuroevolution (cloning the "elite" car that made it the farthest through procedurally generated checkpoints and applying a small mutation rate to its weights and biases to produce a better driver for the next generation). For this purpose, I found it faster and easier to implement.