YEARS ago, when syphilis was introduced to the Old World, the French called it the Italian disease; the Italians called it the French disease; and the Indians called it the Portuguese disease.  Today, there is no such diversity among urbanologists in naming what it is that the automobile has clone to modem cities: They all call it the Los Angeles affliction. Los Angeles has led the United States, as the United States has led the world, in the exaltation of private transportation and the abasement of public transportation.  Its freeway system is unrivalled in reputation, if not ill size (New York’s is bigger); its public transit system, while of considerable size, with the fourth largest bus fleet in the country, is of negligible reputation. Only eight per cent of Los Angeles commuters use public transit, compared with 20 to 30 per cent in San Francisco, Boston, Washington, Chicago, and Philadelphia, and 45 per cent in New York.