Puerto Rico Mail Bears Snail’s Pace Stamp : Postal delivery: Workers blame cultural and language barriers for winning them the title of slowest in the nation. Addresses in Spanish confound English-reading sorting equipment.

Their caps boast: “We Deliver.” And despite a Price Waterhouse survey ranking Puerto Rico the worst in the nation for on-time delivery, postal carriers on the island say they really do.

It’s just that cultural and language barriers--resulting in incorrect address formats that confuse sorting equipment--slow them down.

Postal carrier Hector Quintero takes off his navy cap to mop a sweaty brow, and waves an envelope that illustrates his frustration.

“See? Here’s the biggest problem,” he said. “This is wrong. We’re in Park Boulevard neighborhood. But it’s not written here.”

Easily half of the mail he carried in his leather pouch was misaddressed--with the wrong zip code, no house number, a neighborhood added where there should be none, or none where there should be one.

Earlier, Quintero’s boss, San Juan Postmaster Odarit Tirado, had said that “Park Boulevard” should not be used in the address for this seaside neighborhood.

If the postmaster and his carriers can’t agree on the correct address, how is anyone else supposed to know?

Most people in the U.S. Commonwealth address their mail in Spanish--which is not recognizable to automated sorting equipment programmed in English--and follow the Latin American custom of placing the house or building numbers after the street name.

The English-programmed sorting machines, for instance, can’t read the Spanish word for street--”calle.” So a large percentage of mail must be hand-sorted.

New equipment that can read some Spanish words should come on line this year.

The difficulties in delivering the mail in Puerto Rico also can be traced directly to the island’s own culture.

Towns in Puerto Rico are divided into neighborhoods, adding an extra address line that many company computers cannot accommodate. If that line is missing, carriers in the nearby town of Bayamon, with 52 “No. 1” streets in different neighborhoods, can have delivery problems.

Puerto Ricans tend to be similarly vague giving street directions, seldom knowing the names of roads and directing people instead according to stops on a trolley system that ran 50 years ago, but no more.

The Postal Service has tried to encourage communities to rename their streets. And it has tried to teach large mailers the correct format, such as putting house numbers before street addresses.

Postal officials in San Juan say the 74% on-time score for the March-May quarter in the survey published in June by Price Waterhouse actually was one of its best performances. The national average was 87%.

“From the deepest part of our heart, we know we’re much better than 74,” Tirado said.

He said the post office does “really well” in its own delivery tests, and claimed that some of Price Waterhouse’s letters were incorrectly addressed.

But Sid Schwartz, a postal employee in Washington who works on the testing program, said Price Waterhouse uses several measures to ensure correct addresses.

Puerto Rico can take some consolation in the fact that the island improved on its 68% delivery score last year. In 1991 it scored only 33%, said spokeswoman Mildred Diaz.

“We do everything possible to deliver that mail” rather than send it back, said John Malave, acting manager for the U.S. Postal Service Caribbean area. “Maybe that’s the thing that kills us the most” in delivery tests.

“Our commitment to service must override any score,” he said.