WASHINGTON (AP) - The use of machines instead of humans to sort mail is leading to increases in the num- In e s ber of letters routed to the wrong city and subsequent delays in delivery, the Postal Service says. in r s Postal Service delivery standards call for letters to arrive in one, two or three days, depending on the distance they must travel. The mail agency's 111.a 1jstatistics show that more than 90 per cent of letters are delivered within the service standards, and missent mail is one of the main reasons why some let- delays APters take lSer. A POSTAL SERVICE survey of in tercity mail handled in 30 facilities The Michigan Daily-Thursday, May 4, 1978-Page 11 found 2.2 per cent of the letters were Dorsey said the reasons for missent directed to the wrong cities - often mail include mechanical and human to cities in other parts of the country, errors and improper ZIP codes in the Senior Assistant Postmaster General addresses. E. V. Dorsey has told the Postal Service board. UNDER MECHANIZATION, a "As an example, a letter from New machine brings one letter to a position York City to Washington might wind up in front of a postal worker. The worker in Cleveland. You then have to send it has one secone to punch several digits from Cleveland to Washington. It will of the ZIP code into a keyboard on the be at least one day late," he said. machine. If the letter is going to a dif- Dorsey said the missent rate is higher ferent area, he must punch the first now that machines have taken over three digits but if these numbers are the because "mail used to be sorted twice, dame as his area he must punch the last and that gave you two chances to catch two digits. But the clerk may depress errors. Now, you only have one shot at the wrong key or the machine may it " misfunction.