The shortage of inspectors has been the main cause of long waits to cross the border into the United States. Although Customs and INS share equal responsibility for primary inspections at the border, these agencies have not received comparable increases in inspection staff in recent years. Therefore, increasing the number of Customs inspectors will not necessarily reduce the waiting times for primary vehicle inspections unless INS receives corresponding staff increases. However, the General Accounting Office determined that neither Customs nor INS has an adequate method for determining staffing needs. In addition, difficulties in recruiting and retaining staff along the border have intensified the Customs staffing problems. Customs also reported a need for more administrative and support staff, as in addition to more inspectors. Footnotes and appended table