Traffic Cop is the 53rd level in Chip's Challenge 1. The hint, which suggests the use of the walkers to touch the green button, is misleading; this can be done by pushing the blocks, but it's unreliable and very slow. In fact, no blocks are needed to complete this level, because this level is busted by the use of boosting to go backwards over force floors; one block can bridge across a water strip and speed up the route. Collect the furthest block southeast and push all the way down, then touch the green button in the southeast and bludgeon back over, and return to the exit.
To see how this level would be done with no boost, dropping the score to 449, see the second AVI.