Anchor Road, Canons Road, Canons Way, Lower College Street, Bridge Valley Road, the Portway, some roads around the Cumberland Basin System and others will be closed early morning until mid-afternoon.
The race starts at 09:30 from Anchor Road, Harbourside.
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Unsettled outlook for the rest of the weekend
Unsettled, windy and showery outlook
Lifeguards are back patrolling some of the west country's busiest beaches from today for the summer season.