The Center for Science in the Public Interest wants all state and local governments to post letter grades in the front windows of restaurants showing the restaurant's performance on the most recent food safety inspection.

Restaurants would earn an "A," "B," or "C," depending on a weighted measure of the number and severity of food safety violations. Restaurants earning below a "C" would be closed.

When restaurant owners know that inspection results will be posted publicly, it forces them to make food safety a top priority and is the best motivator for keeping the premises clean and safe, CSPI staff attorney Sarah Klein said. Without public disclosure, restaurants have the incentive to do only what they need to do to stay open, she said.

Dangerous food-handling practices should not be "a hidden shame," she said.

Today, relatively few areas use a restaurant grading system. Allegheny County isn't one of them.

In Los Angeles, where the county has displayed grade cards for 10 years, hospitalizations from foodborne illnesses have declined 20 percent, CSPI said.

-- Patricia Sabatini