Summary: GAO discussed local transit authorities' management of Urban Mass Transportation Administration (UMTA) grants and UMTA grant oversight. GAO found that: (1) grantees did not always comply with grant conditions and federal requirements, even though they certified that they had internal management control systems in place; (2) some grantees' reports did not include enough information to be used as monitoring tools, or UMTA did not use them for that purpose; (3) as of December 31, 1989, UMTA was overseeing about $3.6 billion in active grants to California grantees; (4) San Francisco area grantees received about $1.3 billion, or about 36 percent of the active California grants; (5) although San Francisco area grantees received significant UMTA funding, those funds did not represent the major source of their mass transit funding; (6) California approved several measures intended to relieve traffic congestion; and (7) developing effective strategies to relieve traffic congestion required the cooperation of federal, state, and local governments.