Although floodwaters have subsided in some parts of Bangkok, much of the south of the Thai capital is still under water.
Waters on the important Petchkasem Road are as high as one metre.
Authorities are worried about disruption to the transport system -- Petchkasem Road is the longest in Thailand, and connects the country to Malaysia.
At a news conference in the capital, U.N. Secretary General Ban Ki-moon - on a two day visit to the stricken country - praised the resilience of the Thai people.
(SOUNDBITE) (English) UNITED NATIONS SECRETARY GENERAL BAN KI-MOON:
"I sincerely hope that under the very dynamic leadership of the prime minister, and the whole determined will and resilient will of the Thai people, this crisis will be overcome soon. As I said again repeatedly, the United Nations stands ready to work with the Thai government."
Thai Prime Minister Yingluck Shinawatra said her government has set up a recovery plan for flooded factories.
(SOUNDBITE) (English) THAI PRIME MINISTER YINGLUCK SHINAWATRA:
"We push the emphasis on the restoring, on the rehabilitation, and we have to make sure that every province and some of the industry will be recovered back as soon as possible. We set the target from 45 to 90 days in some of the infrastructure."
The flooding in Thailand - the worst in five decades - has devastated at least 26 provinces since July, claiming at least 560 lives and affecting around two million people.
Nick Rowlands, Reuters.