OASTH is a legal entity governed by private law and was founded in 1957 under Legislative Decree 3721/1957. It provides urban transport for Thessaloniki under financial agreements signed between the Greek State and OASTH.
OASTH's capital is divided into 424 full shares, 346 of which are distributed to about 1,900 small shareholders-drivers, 29 to Thessaloniki KTEL SA (regional bus service), 25 to the OASTH Employee Cooperative and 24 to the OASTH legal entity.
OASTH employs about 2,600 people. Passengers are served by 79 routes, and 4 KTEL routes. Of OASTH's fleet of 618 buses, 544 are on the road transporting approximately 167 million passengers annually.
Since 2005, OASTH has provided a special programme offering free transport to persons with disabilities. Each year, about 12,000 individuals using wheelchairs or with other disabilities are transported using OASTH's 4 specially designed buses (3 run regularly and 1 in reserve).
OASTH has established a telematic system to locate buses and coordinate their routing, as well as providing visual and audio announcements of stops within the buses and at 200 telematic "smart stops" where expected time of arrival is announced.
Of OASTH's 622 buses, 347 are conventional, 249 are articulated, 22 are small and 4 are specially designed to transport persons with disabilities.