Mount Ousley Road is how most of Wollongong gets on and off the escarpment, and it is being rebuilt underneath the traffic still using it. That is the part worth understanding this month.
What changed on Monday
Transport for NSW records that on Monday 17 August traffic changes were implemented on Mount Ousley Road and at its intersection with the M1 Princes Motorway. Motorists have been moved onto a newly built section of Mount Ousley Road, plus a temporary section of road between Mount Ousley Road and the existing M1 intersection.
The August resident update sets out what that means from the driver’s seat, and the two directions now behave differently:
- Southbound, heading to Wollongong: use the existing exit, then a temporary section of road over the new bridge, which connects back into the newly built section of Mount Ousley Road.
- Westbound, coming from Mount Ousley Road: continue to use the existing intersection to turn left to Nowra or right to Sydney onto the M1.
Between Gaynor Avenue and the M1, the road stays one lane in each direction on the new alignment. So the switch is not extra capacity. It is the same number of lanes, moved sideways onto new pavement, to free the old ground for the interchange being built there.
Worth noting for anyone who read the update before the change: the August resident update said the community would be notified in advance of the specific date. The project page now carries that date, in the past tense.
The closure on Wednesday night
Transport for NSW says that because of wet weather impacts, additional work is required. Mount Ousley Road will be fully closed between Gaynor Avenue and the M1 Princes Motorway from 8pm on Wednesday 19 August to 4am on Thursday 20 August 2026.
The M1 Princes Motorway itself remains open in both directions during that closure.
Everything else happening this month
The August update lists the rest, and some of it is easy to be caught by if you only watch Mount Ousley Road.
| Where | When | What |
|---|---|---|
| M1 Princes Motorway between Bulli Tops and Memorial Drive, and Picton Road | Sunday 9, Sunday 16 and Sunday 30 August, 8pm to 4am | Full closure of both, weather permitting. Picton Road eastbound closes at 7.30pm each of those nights so the M1 is clear by 8pm |
| Mount Ousley Road between Gaynor Avenue and the M1 | Wednesday 19 August, 8pm to 4am Thursday | Full closure for the additional work caused by wet weather |
| M1 between Northfields Avenue and Mount Ousley Road | Day and night | 60 km/h reduced speed limit both directions; southbound lane closures at times between 8pm and 6am |
| Mount Ousley Road between Gaynor Avenue and the M1 | Day | Westbound 40 km/h limit and intermittent stoppages with stop/slow traffic control |
| Dumfries Avenue | Day | Full closures at times with detours, and single lane closures with stop/slow control |
| Mount Ousley Road (local), Falder Place, Highbank Place | Day | Single lane closures with stop/slow traffic control at times |
Source: Transport for NSW, Mount Ousley interchange monthly construction update, August 2026, read 18 August 2026. The update marks several of these as dates to be confirmed via electronic message signs and Live Traffic NSW, and the Sunday closures as weather permitting, so treat the table as what is planned rather than what is guaranteed.
Night work runs 7pm to 6am, Mondays to Fridays, from Monday 3 August to Monday 31 August, weather permitting. Standard hours are 7am to 6pm weekdays and 8am to 1pm Saturdays.
Where the project is up to
The interchange is jointly funded by the Australian and NSW governments. As we reported in July from Transport for NSW’s own June update, the project is $390 million, of which $312 million is federal and $78 million state, built by Fulton Hogan, with major work from late 2024 over about four years, and it was 52 per cent complete in June.
One earlier milestone is worth recording because it is permanent. In April the first of two new heavy vehicle safety ramps opened, about 330 metres north of the existing southern-most ramp, and that older southern-most safety ramp is now permanently closed so work can continue on the interchange at the base of the mountain.
When finished, the project’s stated purpose is to separate light and heavy vehicles, improve travel times, support growing freight movements and improve access between the M1 and the Wollongong CBD. The scope includes a southbound heavy vehicle bypass lane, separate southbound off ramps for light and heavy vehicles, a bridge over the M1 with signalised intersections connecting the motorway, Mount Ousley Road and a new access road to the University of Wollongong, a roundabout, several shared paths and pedestrian bridges, and noise walls of five metres and three and a half metres in different sections.
The number the project page still does not give
A completion date. The page describes what is being built and what is happening this month, and our earlier reporting has the project at roughly four years from a late-2024 start, but Transport for NSW does not publish a finish date on the project page we read.
Our reading, offered as opinion. That is not unusual for a project of this size, and the monthly updates are genuinely detailed, which is more than many projects manage. But the practical effect for someone who drives this road is that they can find out what closed on 19 August 2026 and not when the lane count goes back up. The switch on Monday is the halfway marker made visible: from here the work is happening on ground the traffic used to occupy.