A triple dose of disruption is in store for drivers, who will also be held up by rock-blasting and emergency repairs to the Forth Road Bridge.
Drivers have been urged to divert via the Kincardine Bridge, leave “significant” extra time for journeys or take the train instead. ScotRail is adding carriages to 28 weekend services.
The biggest traffic jams are expected to be caused by a six-week project to create a bus lane and resurface the M90 north of the bridge.
A four-mile contraflow will operate between junction one (Admiralty) and three (Halbeath) from Easter Monday, 9 April.
Two lanes will remain open in each direction, but peak-hour delays of 30 minutes are predicted.
However, the Scottish Government’s Transport Scotland agency warned that the hold-ups could top two hours over four weekends from Friday, 20 April, when the southbound carriageway is restricted to one lane.
Some slip roads will also be shut, starting with a two-week closure of the southbound access to the M90 from the A985 at the Admiralty junction in Rosyth from Monday, 2 April.
Late-night drivers also face six months of disruption from rock-blasting at St Margaret’s Hope on the north shore of the Forth.
The Forth Road Bridge and surrounding roads will be closed fortnightly for about 30 minutes from 10pm, starting on Good Friday, 6 April.
The roadworks coincide with emergency repairs to bolts on the main cable of the Forth Road Bridge, which involves four weekends of contraflows from 3am to noon, starting this Saturday.
This will be repeated on 31 March-1 April, and on two further weekends sometime after Easter.
Forth Road Bridge officials said the extra contraflows were because work planned for last weekend had been postponed by strong winds, and more of the bolts that help hold up the bridge deck had been found to need replacing.
A spokesman warned that unprecedented weekday contraflows, causing “extremely significant” disruption, might be required if bad weather again hampered work this weekend.
Transport Scotland roads and infrastructure manager Steven Brown said of the M90 work: “This traffic management is essential to allow the safe and effective delivery of these specialised surfacing works, which are absolutely necessary to ensure the Forth Replacement Crossing project remains on schedule and within budget.
“In the planning of these works we have endeavoured to reduce the inconvenience and disruption to the travelling public, but significant delays unfortunately be unavoidable.
“Our message is simple – avoid using this route if at all possible over these weekends in April and May.”
Neil Greig, of the Institute of Advanced Motorists, said Transport Scotland must ensure its traffic information was accurate.
He said: “This looks like an unwelcome return to the long hold ups and lengthy diversions caused by the major resurfacing work on the Forth Bridge a few years ago.
“Once again weekend travellers will bear the brunt, unless they plan their journeys carefully. For them to do that, Traffic Scotland must ensure that information on websites, local radio and on electronic signs is 100 per cent reliable and accurate.”