In a very busy, but fun town is a small boy car named Junior. Junior has always dreamed of becoming a taxi, something his mother does not support, as she wants him to become a touring car like his father. She catches him reading a book related to Taxi service and she pulls him inside of their home to tell him its time to go to school. But first she fixes him his lunch. His mother wishes him a nice day at school and warns him to stay away from traffic and the railroad crossings.
Soon Junior comes to a crossroads and sees that he can either go to school, or go into the city. He hears the school bell begin to ring and quickly drives into city territory to go explore...
In the city, Junior comes across a street corner and he gets in the front of the line once it makes traffic stop, so that he can ride in a line too. But when it suddenly tells traffic to go, he is thrown in the air by multiple vehicles! He then meets a seemingly peaceful car, which then turns violent when the sign once again changes, so Junior quickly runs and comes to a bigger street and is nearly hit by more cars!
Luckily, Junior randomly finds himself in the middle of a safety zone, meaning he'll be perfectly safe there as long as he stays in it. And so, to help himself Junior picks up the white lines and signs and carries it around with him. This works until he falls into a manhole and comes out from a nearby hole. Soon Junior finds a Gas Station and decides to buy a drink. He can choose from Rose Gas (strawberry), Violet Gas (Grape), and Ethel Gas (Orange). He picks Ethel, which the man warns him is strong but he gives it to him anyway.
After drinking, Junior is much more energetic now! He shows the man, after he thanks him and then drives off, coming by a passing train. Which Junior decides to follow in order to try to pass it but he finds himself slowed down by a "Road Hog". Despite his many beeps, the Road Hog refuses to get out of his way. Soon he manages to trick the road hog when it gets stuck on an upper segment due to having its wheels extended at the moment. Seeing the train approaching, Junior is quick to speed up even more. Junior then passes it instantly and decides he wants to keep doing this.
Upon reaching another crossing, Junior manages to just pass the train! But unknownst to himself, he is now running on Empty and just manages to sputter to the next train crossing, stopping right on top of it! The train comes and hits him!
Junior is taken to the Hospital where a bunch of auto mechanics do surgery and operate on him in hopes of fixing him. His mother is nervously outside awaiting news when the door suddenly opens. Junior comes out and they happily embrace. But when she then tells him she should spank him for what he did, Junior suddenly takes off after another train! He passes by it, but while mocking it he doesn't see another train about to hit him!
Junior lays there on the side of the train tracks dizzily to see that he wasn't hurt at all, it was the train that's been destroyed!