Extending free bus and train services to Jan 15 is aimed at reducing travel costs for people traveling home to the provinces for the long New Year holiday. The measures expired on June 30.
The spokesman said the measures will cost the government around Bt2.18 billion.
The Ministry of Transport reported in August that 400,000 bus passengers and 50,000 rail passengers per day benefited from the measures.
Initiated during the administration of late former prime minister Samak Sundaravej to assist low-income earners in 2008.
Other measures included free electricity for users of less than 90 units per month and free tap water for users of less than 30 cubic metres per month.