The underpass construction site at the Tesco Lotus intersection in Phuket City quickly went under several feet of water, leaving some motorists with no choice except to turn back.
Patong, on the island's west coast, also sank under water in all the usual places.
Delays caused by flooding are one reason why completion of the Tesco Lotus underpass is months overdue . . . and why it continues to flood.
About one billion baht has been earmarked for to relieve chronic flooding in Phuket City and Patong, where officials say there is no serious flooding, just regular ''interruptions to the flow of unwanted water.''
The Phuket-based Bureau of Meteorology was not answering calls at lunchtime.