Rubble is a intelligent orange haul truck who helped Bob build the amusement park. He tends to be worried that he is not fast enough. It was implied he'd return from being a one-time character to a recurring character in Bob the Builder: Ready, Steady, Build!.
Rubble is generally very smart but sometimes worries about speed. However, he learns to work slowly and take his time without rushing. He is also very kind and friendly.