Consider the turtle a symbol of the Joads in general and the plight of the worker in particular. The turtle, like the Joads, is trying to make its way through its life, but is very out of place when crawling across the fast-paced highway…just as the modern worker is left behind by industrialization and the changing economy. The turtle/worker is at the mercy of larger forces. Some might show mercy, like the car that swerves to miss it, but some might also be malign, like the owners who abuse their power. The turtle is also heading their way; it moves on like they do. It is smashed by those going by, and turned over, but it turns itself over and heads on, just as the Joads/workers are trying to do