The anti-terror bollards at the entrance to Parliament Street are now being fitted.
The installation is one of a number of extra security measures to protect the centre of York being finalised in the run-up to Christmas.
These include traffic-slowing measures as used in Edinburgh and in Harrogate.
Last year, York’s footstreets trialled a first phase of measures to prevent traffic coming in during footstreet hours.
Then in August councillors approved plans which recommended implementing a sliding bollard system.
The new temporary safety features are intended to add to the safety of the public, so people can enjoy their plans as normal.
But City of York Council is asking people to arrive in good time for city centre events to allow for increased security checks.
Delivery vehicles will have controlled entry at the permitted times.
‘Prepared, alert and ready’
Tom Brittain, the council’s assistant director of housing and community safety, said:
While very rare, terror attacks in the UK can create a lot of concern.
With our partners in the police, we are making the city centre more secure than it has ever been, and want to reassure everyone who uses it that we are prepared, alert and ready to help protect them.
It’s essential that we all maintain a high level of vigilance and continue to invest in strong protective security measures such as those we’ve installed to deter future attacks.
Superintendent Lindsey Butterfield, Neighbourhood Policing Commander for York and Selby, added: “Although the terrorist threat level has now been lowered to substantial, we still need to remain vigilant and do everything possible to keep people safe.
“These latest measures are a welcome addition to our existing security plans designed to help keep York safe and secure during the festive season and the weeks leading up to it.
“Our Project Servator teams will also be out and about and could appear anywhere, anytime, so if you see them, please stop for a chat and find out how your support can help prevent crime and terrorism.”
Police ask everyone to remain “vigilant and alert but not alarmed”. Please report anything suspicious to the police.
You can pass information in confidence via the Action Counters Terrorism website at gov.uk/ACT where you can find out what to look out for.
You can also report information on 0800 789 321. In an emergency, always call 999.