The vast majority of rivers in the British Isles are natural courses, created by the actions of water over thousands if not hundreds of thousands of years. A very few have been created by man, most of them from the middle ages to the Victorian period. The Huntspill River is newer than that, having been dug in 1940 to provide a constant and reliable water supply to the Royal Ordnance Factory then being built at Puriton. The construction of this bridge, you may fairly think therefore, is easily dated. Alas not. Whatever bridge was built across this new river in 1940 is long gone, with the current crossing being a single span steel girder structure. It is almost certain that this was constructed in the 1960s, prior to the opening of the M5, when the A38 was still the major trunk route from the Midlands to the South West, often grinding to a halt on Summer Weekends as people tried to get further south and west to the coastal resorts.
The bridge takes its name from the former Bleak Farm which stood nearby, but has long since ceased to be a farm. It was clearly built to S3 standard, with a suicide lane down the middle, but has since been relined to a WS2, and now to a standard S2 with the central lane hatched out to protect the turning lanes on either side of the bridge. There are also wide pavements, and the parapets are, typical of their era, metal barriers.