What does the car wreck scene show about Randy, as well as other people in town?

From the text:

In this second Randy made an important decision. Yesterday, he would have stopped instantly. There would have been no question about it. When there was an accident, and someone was hurt, a man stopped. But yesterday was a past period in history, with laws and rules archaic as ancient Rome's. Today the rules had changed, just as Roman law gave way to atavistic barbarism as the empire fell to Hun and Goth. Today a man saved himself and his family and to hell with everyone else.

From this excerpt, we can see that everything has changed.... families came first, family was the priority. There was no time to stop for anyone else when your loved ones were also in danger.