SAN FRANCISCO — It is the kind of thing that makes drivers — not always the calmest breed — absolutely apoplectic.

Every day all over California, officials say, untold masses of people are falsifying, misusing and generally abusing special license plates and windshield placards meant to provide easy access to parking for disabled drivers.

In San Francisco, for example, where roughly 55,000 people hold the placards, the authorities seized more than 2,000 in the last fiscal year, for counterfeiting, use by the wrong person and other reasons. And the city is on an even more torrid pace of confiscations this year.

The problem has gotten so bad that Gov. Arnold Schwarzenegger signed into law last week a measure that increased fines for violators — to up to $1,000 for repeated offenses. It also loosened the hands of parking control officers (a k a meter monitors) to hand out tickets.

The move was hailed by transit officials, who say the result of placard abuse is two-fold.

“Disabled placard abuse does more than just take needed revenue from our transit system,” said Nathaniel P. Ford Sr., the executive director and chief executive of the San Francisco Municipal Transportation Agency. “It actually makes it harder for people with disabilities to find a spot when they need one.”

Placard pretenders are by no means a uniquely Californian problem. One Web site, www.handicappedfraud.org, contains hundreds of testimonials from drivers across the country who suspect others of not playing by the rules.

“Healthy-looking blond woman carrying bags to car,” said one post from Cheektowaga, N.Y. “Loads them with no problem.”

Still, like with many things car-related, California probably has the most culprits. More than 2.5 million Californians — roughly 10 percent of the state’s drivers — have a disabled placard, according to the California Department of Motor Vehicles, nearly triple the number that held the privilege in 1994. And while many are no doubt legitimate placards, parking experts say anecdotal evidence also suggests widespread fraud.

Donald Shoup, a parking expert at the University of California, Los Angeles, said most people in his field think cheating is rampant, using the Capitol in Sacramento — which is often ringed with cars with disabled tags — as an example.

“I once asked a state highway patrol officer who was on duty at the vehicle entrance to the Capitol whether he thought many of the placards were fake or misused,“ Mr. Shoup wrote in an e-mail message. “And he replied, ‘All of them.’ ” (Sacramento, in fact, has a special task force on placard abuse, complete with a hot line.)

The Department of Motor Vehicles says the placards are reserved for people with heart, circulatory or lung disease; missing or paralyzed extremities; and specific sight disorders. It also allows for placards for anyone with “a diagnosed disease or disorder that significantly limits the use of the lower extremities.” And the conditions can be certified by a wide array of medical professionals, including doctors, nurse practitioners, certified midwives and, in some cases, licensed chiropractors.

And that is part of the problem, said John Van Horn, the editor of Parking Today, a Los Angeles trade magazine, who said some unscrupulous medical workers would write a note for a placard for “a sprained ankle.”

“Then they use it for the next five years,“ Mr. Van Horn said of scofflaws.

California law allows those with disabled placards or plates to park at metered spots at no charge, and for an indefinite time. This, critics say, has made placards more than convenient; it has made them a commodity.

Assemblywoman Fiona Ma, a San Francisco Democrat who sponsored the new law, said she had seen placards advertised on Craigslist, as well as fakes.

“They are really hard to identify,” Ms. Ma said. “Only a trained eye could tell the difference.” All of which, she said, has made the law a people pleaser.

“We’ve gotten so many positive responses to this,” she said. “People are saying, ‘It’s about time.’ ”