Plea to motorists over Nicolas Cage visit
The Oscar-winning actor will arrive on stage in Milsom Street at 6.15pm ready to flick the switch at 6.30pm.
But those hoping to witness the event are being urged to get there in plenty of time.
The stage will be at the bottom of Milsom Street near the Russell and Bromley store but TV screens will also be put up so more people will be able to see the action.
Thousands of people are expected to attend as Cage's presence has attracted national attention but event organisers said the street area around the stage could only accommodate 3,000 people and no more would be allowed in.
Extra precautions will also be taken following a similar event in Birmingham earlier this month, which saw 60 people injured as boy band JLS were guest stars, with police and stewards present to ensure public safety.
Police and 50 stewards will be on duty on the night.
Celebrations will begin from 4.30pm with local groups performing on stage, at the request of Cage, who has told organisers that the evening should be about the people of Bath.
Entertainment will include music from students at the City of Bath College and pupils at Kingswood School as well as an appearance from TV presenter and Heart FM DJ Toby Anstis.
City centre manager Andrew Cooper encouraged those travelling into Bath to listen to travel news on the radio and keep an eye on traffic information boards on the edge of the city as well as using the website www.visitbath.co.uk/travelguide to plan their journey.
Milsom Street will close at 4pm.
Once the car parks are full, information will be displayed on the boards and on radio stations.
Park and ride buses will be operating until 9.30pm and motorists will also be able to park for free in the Podium and SouthGate car parks from 4pm.
John Grinnell, manager of The Podium in Northgate Street, which has parking for 550 spaces, said they wanted to help the organisers and ease any congestion by waiving their charges for the evening.
The barriers will remain up until 9pm.
He said: "We realise the problems of parking in Bath and the lights switch-on will present extra problems and we want to do all we can to take some of the stresses and strains away from motorists who will want to come into the city centre for this special occasion."
Simon Pullen, general manager at SouthGate, which has parking for 876 spaces, said: "As co-sponsor of this event with one of our tenants, Boots, we are delighted to contribute towards making the event a success.
"Our car park is brand new and secure and we hope that it will add to the visitor experience on the night."
Mr Cooper said he was looking forward to the event and praised the centres for their gesture.
He said: "The offer of free parking from 4pm will be well received by those visiting the city for the switch-on event.
" People who are unable witness the switch-on ceremony will still be able to enjoy the lights throughout the city.
"We are grateful to SouthGate, Boots, Bath and North East Somerset Council, The Bath Chronicle, Heart FM and Future Bath Plus who have sponsored the event in order to make the launch of Christmas in Bath 2009 a truly memorable event."
Meanwhile Boots, which is one of the sponsors, will be holding a Hollywood Affair day.
Between 3pm and 9pm, the store at SouthGate will be offering champagne and juices along with some festive nibbles for customers and a raffle will be held with lots of goodies for all ages.
Beauty counters will also be offering free makeovers, advice and tips on how to get ready for the red carpet.
Lynne Blackmore, store manager, said: "We are very much looking forward to partnering with the SouthGate centre in sponsoring the switching on of the Christmas lights in Bath this Thursday.
"The store is guaranteed to be full of fun and theatre on the day from our beauty through to our photo offering, and everyone is invited."
The switch on also coincides with the launch of the Bath Christmas market, which draws visitors from around the world.
Park and Ride buses, which usually travel down Milsom Street, will be diverted to Queen Square and will be in operation until 9.30pm.
Cage, who decided earlier this year to sell his two homes in Bath, will meet Mayor of Bath Councillor Colin Barrett before the ceremony to find out more about the city's history and traditions.
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