What is now the A431 was the upper turnpike between Bristol and Bath, north of the River Avon (the lower turnpike, south of the Avon, being the
A4). Both roads were
turnpiked by the Bath Trust in 1707. The Bristol Trust attempted to turnpike the western half of the upper road, but faced opposition from colliers at
Kingswood, and it was not fully completed until the 1740s. By the 19th century, the Upper Bristol Road to Kelston was described as a "pleasing and nearly level ride". When roads were first numbered in 1923, the A431 formed the full extent of the upper Bristol – Bath turnpike as far as the old Post Office at the corner of George Street and
Milsom Street. In 1935, the
Ministry of Transport rerouted the A4 along this route towards Bristol and
Avonmouth, curtailing the A431 to its current eastern point at Newbridge.
Kelston Park landslip In February 2014 the road was closed near
Kelston Park due to a landslip. The closure lasted until 17 November 2014 as the ground continued to move. Deeper pilings were found necessary as the works progressed, taking total repair costs to about £2 million. Local entrepreneur Mike Watts created a private
toll road over agricultural land to bypass the closed section, which opened in August 2014. ==See also==