It has been a route out of the picturesque city since the 12th century, when it was adorned with the severed heads of traitors, but now York’s most infamous historic gate will be shut to traffic as cars are causing it to crumble.

Micklegate bar shut to traffic for the first time yesterday, and will not be a route out of the city for motorists for at least six months, in order to protect the structure, which is part of York’s famous walls.

The outbound traffic passes through the Norman part of the gate, while the inbound traffic, which is unaffected, goes through an arch next to it, built in the 19th century.

Only one car could fit through the original gate at a time, and locals often complained that larger cars were knocking chunks off the historic structure.

Now, only cyclists and pedestrians can use the original gate to pass into and out of the city.

The council said the impact on traffic will be assessed during the period and could become permanent.

Cllr Peter Dew, executive member for transport and planning at the council, said: “The aim of the experiment is to improve the environment in Micklegate by removing a proportion of the through traffic whilst maintaining access for those who need it.