The defunct Omnibus Services Authority (OSA) is to revive with the introduction of the government's mass transportation programme. The Vice-President, Alhaji Aliu Mahama, announced this yesterday when he opened a four-day workshop on ''West African Sub-regional Transportation and Services Development'' in Accra.

It is being attended by Roads and Transport Ministers from the sub-region. He said the government was brining in 250 high occupancy buses ''to be allocated to a restructured Transport Company and the Private Road Transport Operators (unions and associations''). He said 100 of these buses had already been ordered and 25 of them would be ready for use by September.

Alhaji Mahama said since the re-introduction of the shuttle service between Accra and Nsawan last year, ''nor less than 3,000 citizens benefits daily from this service alone''. The Vice-President said the Accra-Tema Rail line was to undergo rehabilitation to offer similar shuttle services to commuters along that route.

He noted that the government in its commitment to poverty infrastructure and services could not be over emphasized. ''Furthermore, road and transport infrastructure is a catalyst to economic growth, especially in the areas of agriculture, industry and tourism and the delivery of social services'', he said. The Vice-President said though taxis and low occupancy vehicles were the main means of motorized travel, the services provided have been irregular, unreliable and generally of poor quality.

''It is evident that the use of low-capacity vehicles create congestion, pollution and frequent breakdowns resulting in loss of man-hours and low productivity,'' he said. That is why the government was seeking to make a major impact in mass transportation he said.

In welcome address, Dr R. W. Anane, Minister of Roads and Transport, said the transport system in the country was chaotic, characterized by congestion in the central business centers of the cities, poor quality of service, high incidence of road accidents and poor environmental standards.

He said these characteristics which reflected the under-development of the transport sector was not peculiar to Ghana but in the sub-region as a whole. He was therefore grateful to the Federal Transport Administration of the United States of America for the workshop, which would assist in the evolvement of options and recommendations to improve the transport systems.

Ms Elizabeth Raspolic, Charge d'Affaires of the American Embassy, said the American government '' hopes to finalize agreements later this year for the opening of the first Technology Transfer Centre for West Africa'' in Ghana.