Study data came from a telephone survey of 17 U.S. attorneys' offices, onsite interviews with 90 criminal justice personnel in 6 Federal jurisdictions, examination of 546 cases, and analysis of FBI data on 700 robbery and embezzlement cases. In addition, a mail survey was conducted in all 94 U.S. attorneys' offices, and published court statistics were examined. A study group consisting of six jurisdictions (New Jersey, Colorado, northern California, southern Florida, southern New York, and northern Illinois) was used. A total of 97 percent of cases complied with the law's 30-day limit in the year ending June 30, 1983, the corresponding figure for the study group was 94 percent. The number of cases taking an extermely long time to disposition has declined in recent years. The law has also encouraged U.S. attorneys' offices and the courts to review their case management policies and procedures and to take steps to improve efficiency. However, the law appears to have had some unintended consequences. The Government appears to have partly responded by controlling case intake and by moving as much case preparation as possible outside the mandated intervals. Some confusion exists over the application of the excludable delay provisions. However, these consequences appear to be relatively minor. The Judicial Conference should update its guidelines to promote greater uniformity in the application of the excludable time provisions and other provisions of the Act. Local field offices, U.S. attorneys' offices, and individual courts should review their policies and procedures regularly to see that they conform to both the letter and the spirit of the law. Additional training is also needed to ensure that staff are familiar with the law's provisions and that no cases are dismissed due to oversight or misunderstanding of the law. Data tables and footnotes are supplied. (Author summary modified)