A car is on a one-dimensional track, positioned between two "mountains". The goal is to drive up the mountain on the right; however, the car's engine is not strong enough to scale the mountain in a single pass. Therefore, the only way to succeed is to drive back and forth to build up momentum.

This problem was first described by Andrew Moore in his PhD thesis [Moore90].

[Moore90]A Moore, Efficient Memory-Based Learning for Robot Control, PhD thesis, University of Cambridge, 1990.
RandomAgent on MountainCar-v0