As U.S. home prices continue to rise and apartment vacancy rates drop, the lack of affordable housing has even edged the most vulnerable — the homeless — out of their cars and into the streets.

The Wall Street Journal reports that at least 70 cities in the nation have passed laws that ban people from living in their vehicles. In Palo Alto, Calif., people living in their cars face a fine as high as $1,000 or a six-month jail sentence. These measures are a response to homelessness, which has increased in certain metro areas during the recession, despite a nationwide dip:

“With the dearth of affordable housing for folks, sometime they have no other option,” said Robert Dolci, homesless-concerns coordinator for Santa Clara County. He said that with a low vacancy rate and rising rents, landlords aren’t necessarily eager to rent to people with spotty employment and credit or limited government housing subsidies.

Palo Alto has withheld from enforcing the ban for now, the Journal reports, awaiting the result of an appeal to a similar law in Los Angeles. A decision is expected later this year.