But are insurance companies going too far in considering other factors?
Bob Hunter at the Consumer Federation of America thinks so.
He and the federation set out recently to find out why so many drivers are uninsured even though most states require it.
The examples they found are like one woman in Miami, who's single with a flawless driving record, but only a high school diploma and in a low-paying job.
"They'll charge her for basic coverage, required by the state, $4024 dollars in Miami," Hunter notes.
If she gets married, a college degree and a higher paying job the premium drops to about $600 a year.
Hunter, who used to be the insurance commissioner in Texas, accuses some insurance companies of using income as way to discriminate against the poor.
"They're trying to avoid the poor, and they know that if they just don't write them, they'll be accused of red lining. I think they're just trying to price them out of the market," Hunter says.
The industry flatly denies that, and the Insurance Information Institute's website says factors like place of residence are fair game in determining rates.
The Consumer Federation wants the states to step in.
"They have to say look, we're requiring this insurance, we should do something to make sure people can afford it, who are good drivers," Hunter argues.
In the meantime, the advice is the standard: Shop and compare.