(Los Angeles in 1957 finally bowed to the skyscraper.) And without high density in the core, rapid-transit systems cannot be maintained economically, let alone built from scratch at today's prices.

However, the building of freeways and garages cannot continue forever. The new interchange among the four Los Angeles freeways, including the grade-constructed accesses, occupies by itself no less than eighty acres of downtown land, one-eighth of a square mile, an area about the size of Rockefeller Center in New York. It is hard to believe that this mass of intertwined concrete constitutes what the law calls ``the highest and best use'' of centrally located urban land. As it affects the city's fiscal situation, such an interchange is ruinous; it removes forever from the tax rolls property which should be taxed to pay for the city services. Subways improved land values without taking away land; freeways boost valuation less (because the garages they require are not prime buildings by a long shot), and reduce the acreage that can be taxed. Downtown Los Angeles is already two-thirds freeway, interchange, street, parking lot and garage -- one of those preposterous ``if'' statistics has already come to pass.

The freeway with narrowly spaced interchanges concentrates and mitigates the access problem, but it also acts inevitably as an artificial, isolating boundary. City planners do not always use this boundary as effectively as they might. Less ambitious freeway plans may be more successful -- especially when the roadways and interchanges are raised, allowing for cross access at many points and providing parking areas below the ramp.