Work to pave Broad Street in St Helier and give pedestrians priority is expected to take until the end of 2027.
The first phase will start on 1 September and take until March 2026. Buses will be re-routed.
The initial work will take in the area between LLoyds Bank and the Post Office and will include a flush granite surface similar to what has just been laid at New Cut, bespoke street furniture and planting.
The government says the aim of the 'Broad Street Public Realm Improvements' is to make town more vibrant and attractive.
Read: Opinion split on Broad Street transformation plans

The New Cut/King Street junction has had a compass design set into the ground. Brass lettering references key local destinations and, in the centre is a representation of the Elias Le Gros map.
The government says further limiting traffic through that part of town has led to an increase in al fresco dining applications.
Road closures will be in place from Lloyds Bank to the Post Office.

Pedestrians will be able to use the area during the works, but cyclists will have to dismount.
We're told three further phases of work will follow, with an expected completion date of autumn 2027.

Fort Regent vision 'was never matched' by a budget that could deliver it, says JHA
Buzzing! Bears and Bees coming to Jersey
JCG Year 7 Choir learn and perform wartime song
Gas bills to go up by 5% in December
Second memorial plaque vandalised at Millennium Park
'They got our hopes up': Young islanders disappointed as Fort Regent plans stall
Electricity prices in Jersey to rise by 2.5%
Minister says he has been 'slated' and his family taken 'abusive' phone-calls over economic growth comments