The resurfacing of Les Banques in St Sampson's will begin on 1 June.
The work will include changes to the layout aimed at making it safer to cross the busy road near the Red Lion roundabout.
A new central refuge and illuminated bollards will be put in just south of the slipway.
Guernsey's States says that will make it easier and safer for wheelchair users, people with buggies and those with visual impairments.
Work is due to start on 1 June and take four weeks. Temporary traffic signals will be in place, and signs will be put up advising of the change of access to and from the Grand Bouet.
Motorists are being advised to expect delays throughout , and the footpath and cycle path will be closed during the final phase of the works.
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