Length:

154 km (Harvey to Bunbury: 46 km)

Termini:

Northern: Armadale Rd (SR14) and Albany Hwy (SR30), Armadale

Southern: Robertson Dr (NR1 / SR10) and Picton Rd (unnumbered), Glen Iris

Miscellaneous:

Continues as NR1 from Bunbury

Suburbs, Towns & Localities Along Route:

Wokalup, Benger, Brunswick Junction, Roelands, Waterloo, Picton East, Picton and Glen Iris (Bunbury)

Current: 20

Former: 1

Road Authority Internal Classification: ¹

H009

General Information:

State Route 20 is a north-south route connecting the southwestern suburbs of Perth with Western Australia's third largest city, Bunbury.

Once the primary thoroughfare connecting Perth to the southwest, this route links a multitude of small towns that owe their existence to the 19th-century construction of the railway line that closely parallels much of State Route 20's length.

The route is rural highway standard for most of it, and services residential, commercial, light industrial and agricultural areas.

1 July 1853: Colonial Secretary Frederick Barlee announced a new proposal for a Perth–Pinjarra–Bunbury route along the foothills of the Darling Scarp. ²

1864: Work commences on construction of the route announced in 1853 by two gangs of convicts.

1876: Construction completed of the route announced in 1853.

July 1941: The name South Western Highway officially adopted. ³

1980s: National Route 1 rerouted via Old Coast Road, SR20 introduced to the former NR1 alignment between Armadale and Bunbury.

2006: Two additional passing lanes added to the highway north of Brunswick Junction. ⁴

April 2022: Work commenced on construction of the interchange with Bunbury Outer Ring Road (BORR) at Waterloo, near the roadhouse. ⁵

2024: State Route 107 decommissioned between Bunbury and Roelands, extinguishing the duplex with State Route 20. ⁶

Bunbury to Harvey

Advance Directional Sign:

Northbound AD sign on Picton Road in Bunbury approaching the South Western Highway / Bunbury Bypass / Robertson Drive intersection. July 2008.

Image © Paul Rands

Distance Sign:

Looking northeast at Glen Iris near the Preston River. December 2007.

Image © Paul Rands

Advance Directional Sign:

AD sign at Picton approaching Willinge Dr (formerly Picton-Boyanup Rd). April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Willinge Drive Intersection:

Looking northeast at the Willinge Dr (formerly Picton-Boyanup Rd) intersection. April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Willinge Drive:

Corner of South Western Hwy (SR20) and Willinge Dr at Picton, April 2016.

Image © Paul Rands

Advance Directional Sign:

AD sign on Willinge Dr at Picton approaching South Western Hwy (SR20), April 2016.

Image © Paul Rands

Intersection Directional Sign:

ID sign facing Willinge Dr at the junction with South Western Hwy (SR20) at Picton, April 2016.

Image © Paul Rands

Intersection Directional Sign:

ID sign facing Willinge Dr at the junction with South Western Hwy (SR20) at Picton, April 2016.

Image © Paul Rands

Distance Sign:

RD sign as you head northeast at Picton, December 2007.

Image © Paul Rands

Waterloo Road:

Corner of South Western Hwy (SR20) and Waterloo Rd at Waterloo, April 2018.

Image © Paul Rands

Distance Sign:

RD sign as you head northeast at Waterloo, December 2007.

Image © Paul Rands

Collie River:

Crossing the Collie River at Burekup. December 2007.

Image © Paul Rands

Approaching Raymond Road / Coalfields Hwy Junction:

Heading northeast at Burekup approaching Raymond Rd (left turn) and Coalfields Hwy (SR107) (right turn), December 2007.

Image © Paul Rands

Coalfields Highway:

Corner of South Western Hwy (SR20) and Coalfields Hwy (SR107 / TW355) at Roelands, April 2018.

Image © Paul Rands

Distance Sign:

RD sign as you head northbound at Brunswick Junction, July 2008.

Image © Paul Rands

Entering Benger:

Entering the village of Benger on the South Western Highway, July 2008.

Image © Paul Rands

Welcome to Wokalup:

Northbound sign announcing the town of Wokalup. July 2008.

Image © Paul Rands

South Western Highway through Wokalup:

Looking northbound at Wokalup, July 2008.

Image © Paul Rands

Harvey to Bunbury

Entering Wokalup:

South Western Hwy (SR20) as it enters the town of Wokalup, April 2016.

Image © Paul Rands

Entering Wokalup:

Southbound as you enter the town of Wokalup, December 2007. This sign has since been relocated.

Image © Paul Rands

Level Crossing:

Southbound at Wokalup as you cross the Bunbury to Perth railway line, December 2007.

Image © Paul Rands

Wokalup Town Centre:

Heading southbound through Wokalup near Dixon Av, December 2007.

Image © Paul Rands

Wokalup Town Centre:

Looking southbound, April 2016.

Image © Paul Rands

Trailblazer:

SR20 trailblazer near Mornington Rd at Wokalup, April 2016.

Image © Paul Rands

Entering Benger:

Town sign for Benger. Southbound, April 2016.

Image © Paul Rands

Entering Brunswick Junction:

Entering the town of Brunswick Junction, April 2016.

Image © Paul Rands

Brunswick River:

Crossing the Brunswick River in Brunswick Jct. Southbound, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Brunswick Junction:

Brunswick Junction CBD outside the post office, southbound, April 2016.

Image © Paul Rands

Distance Sign:

RD sign as you leave Brunswick Jct. Southbound, April 2016.

Image © Paul Rands

Advance Directional Sign:

AD sign approaching Government Road, Roelands. Southbound, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Advance Directional Sign:

AD sign approaching Coalfields Hwy (SR107) and Raymond Rd at Burekup, southbound, December 2007.

Image © Paul Rands

Supplemental Advance Directional Sign:

Supplemental AD sign approaching Coalfields Rd (SR107) at Burekup, April 2016.

Image © Paul Rands

Corner of South Western Hwy & Coalfields Hwy:

Burekup at the intersection with SR107, Coalfields Hwy. Southbound, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Raymond Road Intersection:

Intersection with Raymond Rd. Southbound, December 2007.

Image © Paul Rands

Collie River:

Crossing the Collie River in Burekup. Southbound, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Shenton Road Intersection:

Approaching Shenton Rd Burekup, southbound, December 2007.

Image © Paul Rands

Approaching Waterloo Road:

AD sign in Waterloo. Southbound, April 2016.

Image © Paul Rands

Waterloo Road Intersection:

Southbound through the junction with Waterloo Road in Waterloo, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Distance Sign:

Southbound RD sign at Waterloo, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Hynes Road:

Corner of South Western Hwy (SR20) and Hynes Rd at Waterloo, April 2016.

Image © Paul Rands

Entering Bunbury City:

Council signage indicating you're entering the greater Bunbury area, southbound at Picton, December 2007.

Image © Paul Rands

Bunbury Town Sign:

Entering Bunbury area at the suburb of Picton, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

AD Sign:

Advance directional sign approaching Willinge Dr (formerly Picton-Boyanup Rd) at Picton, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Willinge Dr Intersection:

ID sign at Willinge Dr (formerly Picton-Boyanup Rd) in the industrial suburb of Picton, April 2016. Click or tap here for a photo of this location by Paul Rands from December 2007.

Image © Paul Rands

Distance Sign:

Signage indicating distance to Bunbury CBD, Picton, December 2007.

Image © Paul Rands

Preston River:

Crossing the Preston River at Picton, December 2007.

Image © Paul Rands

Advance Directional Sign:

AD sign approaching the corner of South Western Hwy, Roberston Dr and Picton Rd at Glen Iris. This is the southern terminus of SR20, South Western Hwy continues as NR1 / SR10, turning left at the upcoming intersection, December 2007.

Image © Paul Rands