Tokyo Parking / Rush Hour

Designed by Nob Yoshigahara 1995, Rush Hour by ThinkFun.
(Tokyo Parking, wood tray and 16 wood pieces in cardboard box, 5.8" x 5.8" x 1";
Rush Hour, Plastic tray and 16 plastic pieces with storage bag, 6" x 5.5" x 2")

Rush Hour began with a license to Tokyo Parking, which comes with 36 problems. The Rush Hour problems are on cards in a tray that slides out of the front; four more problems are added for a total of 40 cards, where each has a solution on the reverse side. Each problem uses a subset of the pieces. The goal is to slide the pieces so as to be able to slide out a designated piece (the dark block in the Tokyo Parking directions or the piece labeled X on the Rush Hour cards) through gap on the right side of the tray. Pieces may only move in the direction of their longest dimension (that is, thinking of the pieces as vehicles, they can only move forward or in reverse); the Rush Hour tray has tracks that enforce this rule.

Rush Hour has been made in a number of variations, including metallic pieces, more problem cards, railroad cars, a junior version, and different packaging. Problem 36 of Tokyo parking is the same as problem 40 of Rush Hour (with a solution of 51 moves).

Further Reading
Rush Hour History, from:

Tokyo Parking Problems

Tokyo Parking / Rush Hour Highest Numbered Problem
Tokyo Parking problem 36 (Rush Hour problem 40) can be solved in 51 straight-line movements; here is a diagram of the starting position, and the pieces at the finish:

Tokyo Parking 36 / Rush Hour 40 Solution (51 Moves)