Donostia-San Sebastián City Council offers the city public transport service to all passengers through the Compañía del Tranvía de San Sebastián (CTSS).
Currently the CTSS employs 446 workers of which 346 are bus drivers.
The fleet is made up of 121 buses, 84 of which are 12-m models, 3 are 9-m models, 26 are 18-m models and 8 are minibuses. The fleet is constantly being updated so that in the near future all vehicles will have a low platform easing accessibility. Currently, the 100% of vehicles have a low platform easing accessibility.
The CTSS currently has 27 bus lines that link the different districts in Donostia on a daily basis. At weekends there is a Night Owl bus service that offers nine different routes. Likewise, the lines 28-AMARA-HOSPITALES, 5-BENTABERRI and 13-ALTZA, they have the certification AENOR according to the norm UNE-EN 13816 in travelers' public transport.
Azken urteetan 26.002.755 (2004), 26.219.165 (2005), 26.670.005 (2006) , 27.360.638 (2007), 28.002.785 (2008), 28.460.380 (2009) eta 2010 urtean 29.015.007 bidaiarik erabili zituzten Konpainiaren lineak. Datu horien argitan, Donostia da hiri autobusak gehien erabiltzen dituen hiria, berak baitu biztanleko bidaiari ratio handiena.
In 2010, more than 6,400,000 kilometres were covered around the city by the entire fleet of buses.
The fleet has SAE equipment with GPRS communications that determines the location of each bus at all times and informs users of the estimated time of arrival at each of the 83 stops that have information panels installed. The buses are also equipped with a multimedia information system that, in addition to providing arrival times and CTSS news, is also an information and entertainment channel. Additionally, all the fleet is equipped with a system of videovigilancia.
The CTSS also boasts professional systems of planning and optimising the number of buses and drivers, contactless and contact payment methods in the buses, modern installations for maintenance and repair work, along with a Wifi network in depots to exchange information between the equipment installed in the buses and the servers of the different integrated systems.