The Orwell Bridge near Ipswich has shut to drivers as wind speeds that could reach 90mph arrive in Suffolk.
National Highways, which manages the road network, has said the bridge is expected to be closed for most of the day due to Storm Eunice.
Once closed, National Highways will continue to monitor wind speeds closely before making a decision about when to reopen the bridge.
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The diversion route is via the A1156, A1189 and A1214 through Ipswich.
It is the first time the Orwell Bridge has completely shut to drivers since a 40mph speed limit was introduced in high winds.
The Met Office has issued an amber weather warning for most of Friday in Suffolk, meaning the conditions present a danger to life.
For up-to-date information about the county's roads, visit our LIVE Suffolk traffic map.
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