This is the dramatic moment a crane collapsed injuring three people at a notorious 'never-ending road construction' in Thailand.

The building equipment was hoisting a massive steel beam when it toppled onto the parallel carriageway on Rama II Road in Samut Sakhon on Sunday.

The falling boom snagged on high-voltage power lines before smashing into a passing pickup truck, burying the vehicle under debris.

Authorities said the crane operator, the truck driver and his passenger were injured. They were taken to Mahachai and Samut Sakhon Hospitals for treatment.

Samut Sakhon Governor Narit Niramaiwong visited the site to assess the damage following the collapse.

Traffic police diverted cars for crane recovery operations.

Highway officials said the road was expected to be fully reopened soon as the fallen crane boom had been removed.

The Department of Highways said the accident occurred while steel beams were being installed for the Bang Khun Thian - Ban Phaeo Elevated Road.

Construction has temporarily been halted as the contractor was ordered to draft an accident prevention and resolution plan.

Rama II Road in Thailand is notorious for its troubled plans and frequent delays, earning it a reputation as a 'never-ending road construction'.

The highway has also been plagued by accidents, deaths and safety concerns along the route.