Under a new Transportation Department program, travel agents and airline reservation clerks now have on-time performance information about specific flights at their disposal through their computerized reservation systems. The information is required under regulations put in effect earlier this year. Airlines are required to provide for each flight a single-digit code indicating how often the flights had arrived on time during the previous month. A flight that arrived within 15 minutes of its scheduled arrival between 80% and 89% of the time, for example, would carry the digit "8" as part of the computerized information used by travel agents or airline reservation clerks. Consumer advocates noted, however, that agents are not required to provide the information unless specifically asked.