Bennet Road has been closed at its junction with the A33 since 18 October, blocking drivers from using that route to Green Park and the Select Car Leasing Stadium.
Access to local businesses and Reading Borough Council's depot is being kept via the junction with Basingstoke Road, while Thames Water carries out a major sewer repair under rolling closure permits.
Work has become far more complex than first thought. A trunk sewer just over a metre wide collapsed in October and, during investigations, a sinkhole was found below ground. A second, probably linked, sinkhole has since been discovered.
Engineers are dealing with deep, unstable ground, high groundwater levels, a high-voltage cable that had to be moved and the need to manage wastewater. Thames Water has had to dig a shaft about 10.5m deep and says extra stabilisation is needed.
Thames Water and the council say the repairs are likely to continue until the end of July. They hope to open a single lane to turn left out of Bennet Road onto the A33 in mid-June, but that will depend on safety checks.
Local firms say the closure is hurting trade and some customers assume they have shut, though businesses remain open. Staff at one garage said they do not expect the junction to reopen any time soon.
James Aldridge, Local Democracy Reporter
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