Transport authorities are recommending detours to motorists as the collapse of a new expressway on Saturday seriously damaged an existing Bangkok-Thon Buri expressway ramp which connects to Rama II Road, a main southbound highway, and its complete reopening will take about a month.
Surachet Laophulsuk, governor of the Expressway Authority of Thailand (Exat), said near the collapse site on Sunday that police expected very heavy traffic congestion in the area on Monday as the collapse blocked both inbound and outbound traffic on the Chalerm Maha Nakhon expressway ramp near the Dao Khanong toll plaza.
Debris could be removed in seven days and the inbound side of the ramp of the Chalerm Maha Nakhon expressway could be reopened within the seven-day period, he said.
However, the collapse also damaged one span of the outbound side. New beams would be cast and installed as a replacement. "That will take 30 days to complete," Mr Surachet said.
The damaged section of the Chalerm Maha Nakhon expressway connects to the Rama IX Bridge which links Bangkok and Thon Buri across the Chao Phraya River. The damaged section also links with Bangkok's main route to the South, Rama II Road (Highway 35).
The Exat governor said that two temporary lanes could be built for inbound traffic to the Chalerm Maha Nakhon expressway but he would like motorists to avoid the Rama IX Bridge. “Motorists should leave home for work at 5.30am,” he said.
On the investigation into the cause of the collapse, Mr Surachet said that it could begin after debris was removed from the site and he wanted officials concerned to conclude the probe in 20 days after the debris removal.
“There could be many possible causes including land subsidence,” he said.
The collapse happened to the new Rama III-Dao Khanong-Bangkok Outer Western Ring Road expressway project which was being built above the Chalerm Maha Nakhon expressway in Dao Khanong area and above Rama II Road that intersects with the Bangkok Outer Western Ring Road.
The Exat governor said that collapses are possible during construction, but once complete the new expressway, designed to be five kilometres long, will not collapse.
Withaya Yamoung, deputy permanent secretary for transport who is also an Exat board member, said that to avoid the Rama IX Bridge, motorists between Bangkok and Thon Buri area should use the new Thosamarachan Bridge, Bhumibol 1 and Bhumibol 2 Bridges, Sathon Road and the southern section of the Industrial Ring Road.
Exat chairman Apirat Chaiwongnoi who is also the director-general of the Highways Department said the collapse happened on a main traffic route and parties concerned would try to reopen it as soon as possible.
Meanwhile, police advised motorists on Rama II Road to use Suksawat Road and either enter or exit the Chalerm Maha Nakhon Expressway through the Suksawat toll plaza.
Police also recommended drivers use Phetkasem and Borommaratchachonnani roads to avoid Rama II Road which connected to the collapse site.
On Sunday there were reports that a Myanmar man who was an injured victim in the incident was pronounced dead at Taksin Hospital on late Saturday and the death toll rose to six.
Five previously reported fatalities comprised a 39-year-old Thai engineer, two Thai workers and two foreign workers.