Glencrutchery Road bus lane and Governor's Dip diversion also to be removed
The one-way system on Douglas promenade will be removed next week, three months earlier than initially scheduled.
The Department of Infrastructure has announced the Summerhill junction will open on Tuesday next week, which will allow traffic to head south.
The changes will also see the diversion at Governor's Dip end, and the bus and cycle lane on Glencrutchery Road removed.
The 20mph speed limit will continue, while traffic will use the walkway on Loch Promenade
The Broadway junction will remain closed until the end of October.