The number of U.S. high-speed Internet access lines increased 57 percent during the first half of 2000, the Federal Communications Commission reported Tuesday, for a total of 4.3 million lines. About 2.8 million of those lines offered speed in excess of 200 kbps in both directions, up from 2 million at the end of 1999, the FCC said. Some 70 percent of U.S. zip codes now have such lines, up from 59 percent. DSL lines increased 157 percent during the period to nearly one million lines, while cable saw the second-fastest high-speed growth, at 59 percent to 2.2 million lines. The data were compiled by the FCC from information provided by the telecom industry and is part of a study the commission performs twice a year.