The Federal Government says the Third Mainland Bridge will be closed on Friday at midnight and will not be reopened until January 2021.
Minister of Works and Housing, Mr Babatunde Fashola, who confirmed this at a briefing in Abuja on Tuesday, called on motorists in Lagos to be patient with the repairs.
Mr Fashola explained that the maintenance of the busiest bridge in the country was aimed at replacing damaged components for a better motoring experience.
The maintenance is to be carried out on a length of 3.5 kilometres out of the 11.8 kilometres of the bridge.
The planned duration of the closure and the importance of the bridge to activities in Lagos which has battled traffic for years has led to concerns.
Mr Fashola acknowledged that the closure will lead to hardship in the short term but explained that there was no other way to carry out the maintenance work without closing the bridge.
He added that it was better to bear six months of work and closure than to allow the bridge to collapse, a development that would take years to fix.