PLTO Chief Adcha Buachan noted that in some areas where cars were unable to pass due to floodwaters, buses and large vehicles could continue through the water across the road.
So far interprovincial bus services had not been affected, Mr Adcha said.
Thalang Police reported that Thepkrasattri Rd northbound from the U-turn in front of the Isuzu dealership in Koh Kaew to Heroines Monument remained heavily affected.
Earlier this morning traffic was closed due to flooding.
Northbound traffic was redirected onto the southbound lanes so motorists could continue their journey. Smaller vehicles were redirected to an alternative route to allow larger vehicles to use the main road.
Officials reported that much of the flooding in the area was due to continuous rain and water overflowing from the Bang Neow Dam reservoir in Srisoonthorn.
Other sections of Thepkrasattri Rd affected included the southbound lanes in front of the Eua Athon public housing estate in Moo 1, Srisoonthorn, where the road was reduced to two lanes.
Northbound lanes in front of Bang Khanun Forest Park in Moo 5, Thepkrasattri, were also affected.
Tha Chatchai Police reported that no major roads had affected traffic heading onto or off the island.
The PLTO and police advised that the situation regarding floodwaters affecting major roads was continually changing, with floodwaters receding in some areas, but rising in others.
PLTO Chief Mr Adcha said his office will continue to monitor and report on the situation.