Length:

33 km

Termini:

Northern: Federal Highway (M23), Majura Parkway (M23) and Horse Park Drive interchange, near Watson

Southern: Monaro Highway (B23) at Williamsdale

Miscellaneous:

Continues as B23 at the NSW Border at Williamsdale

Suburbs, Towns & Localities Along Route:

Watson, Dickson, Downer, Lyneham, Braddon, Turner, Civic, Acton, Parkes, Yarralumla, Capital Hill, Barton, Forrest, Kingston, Manuka, Griffith, Fyshwick, Narrabundah, Symonston, Hume, Gilmore, Richardson, Theodore, Royalla and Williamsdale

Current: A23

Former: B23 23

A23 is an urban arterial route through Canberra. It was once the main route through the city, but now superseded by the Majura Parkway / Monaro Highway (M23) corridor.

The route consists of several roads that featured on the original city design by Walter Burley Griffin, who won a design contest during the early 20th century to design Australia's national capital.

Between Ginns Gap and Fyshwick, A23 is made up entirely of dual carriageway road between 4 and 6 lanes wide, and passes through residential and commercial zones, as well as the Parlimentary Triangle, which includes Lake Burley Griffin, Parliament House and several government institutions.

The route from Fyshwick to Gilmore is divided motorway and arterial road standard, with at least 2 lanes in each direction, then from Gilmore to Williamsdale, the route is undivided rural highway standard with occasional overtaking lanes.

Traffic types vary considerably along the route. Because of the proximity to the industrial areas of Fyshwick, Hume and to a lesser extent, Symonston, there is quite a lot of heavy vehicles using the route. Other traffic includes commuters travelling to and from Civic and South Canberra to Tuggeranong and during Winter, ski traffic making its way to and from the NSW snowfields, south of Cooma.

Between the spans on the southern side of the Commonwealth Avenue Bridge over Lake Burley Griffin, there's two granite stones from the 1817 Waterloo Bridge across the River Thames in London. These were presented to Australia after the 1817 Waterloo Bridge was demolished in the 1940s and replaced by a modern structure. A plaque reads, in part, "Stones such as these from the bridge were presented to Australia and other parts of the British world to further historic links in the British Commonwealth of Nations".

Federal Highway:

September 1928: Sydney-Canberra Road declared as Federal Highway. ¹

1929: Work started on Federal Highway. ²

June 1929: Contract awarded to John Fowler (Aust) Ltd, to construct a 6 mile section of highway from Canberra (now Lyneham) to the Federal Capital Territory boundary of earthwork and gravel. ³

1930: Completion of ACT section of Federal Highway. ⁴

May 1961: Work commenced on straightening Federal Hwy and included an access road to Downer. ⁵

September 1961: Northbourne Avenue name extended along Federal Highway to Stirling Avenue at Watson. ⁶

February 1962: Construction of a turning circle at the entrance to the Starlight Drive-In Theatre on the Federal Highway completed. ⁷

December 1965: Contract awarded to Thompson Constructions to widen and re-align a 1 mile section of Federal Highway near the border. ⁸

May 1966: Widening and realingment works commence on Federal Hwy near border. ⁹

May 1973: Installation begins of new direction signs, dark green with white reflectorised lettering, on the Federal Highway. ¹⁰

1974: Upgrade from National Route 23 to National Highway 23 to reflect the route being included in the federally funded National Highway system. ¹¹

November 1994: Plans to upgrade Federal Highway to dual carriageway from Stirling Avenue to Sutton Road (in NSW) submitted to Federal Minister for Transport for review. ¹²

August 1998: Variation of the territory plan to allow construction of the Majura Road / Horse Park Drive interchange near Watson, and the duplication of Federal Highway from Watson to NSW border. ¹³

1999: Work commenced on upgrading the section of highway between the border and Stirling Avenue Watson to dual carriageway.

December 2002: Completion of the dual carriageways between Stirling Avenue and NSW Border.

2016: A23 signposted on Federal Highway between ACT-NSW Border and interchange with Majura Parkway and Horse Park Drive.

Northbourne Avenue:

1911: Planning of Northbourne Avenue by Walter Burley Griffin. ¹⁴

20 September 1928: Northbourne Avenue name gazetted. ¹⁵

1937: Mercury vapour street lights installed on Northbourne Avenue. ¹⁶

1946: bituminous seal on Northbourne Avenue extended to the junction with Gould Street, Turner. ¹⁷

October 1951: One way directional signs installed on divided section of Northbourne Avenue between Civic and Haig Park. ¹⁸

1957: Duplication of Northbourne Avenue to Barton Highway intersection at Lyneham. ¹⁹

October 1959: Installation of brighter street lights on Northboune Avenue, Civic. ²⁰

1960: Work started to extend Northbourne Avenue to City Hill, and the construction of Vernon Circle. ²¹

August 1962: Northbourne Avenue dual carriageways marked with 2 lanes in each direction. ²²

1964: Widening of Northbourne Avenue between Cooyong St and London Cct, Civic. ²³

24 August 1965: Installation begins of traffic lights on the intersections of Northbourne Avenue with London Circuit and also Alinga Street and Cooyong Street. ²⁴

23 October 1965: Canberra's first traffic lights came into operation. The lights were installed at the intersection of London Circuit and Northbourne Avenue and Cooyong Street and Alinga Street. In addition to the lights, give-way signs have were installed on the Northbourne Avenue median strip at the Alinga Street crossing to ensure a free flow of traffic on both carriageways of Northbourne Avenue. ²⁵

1965: Upgrade of street lights almost the entire length of Northbourne Avenue from London Circuit north to Antill Street. ²⁶

April 1966: Closure of median strip as part of widening works to Northbourne Avenue at the Greenway Street junction. ²⁷

September 1966: Completion of widening of Northbourne Avenue north of Civic. ²⁸

November 1966: Overhead directional sign gantry tested on Northbourne Avenue approaching Macarthur and Wakefield Avenues. The test was conducted by ANU students in conjuction with NCDC and 3M. The test was deemed unsuccessful. ²⁹

9 December 1968: Traffic lights at the corner of Northbourne Avenue and Wakefield Avenue switched on. ³⁰

6 May 1969: Southbound lanes of Northbourne Avenue extension and Vernon Circle opened to traffic. ³¹

1969: Work commenced on widening Northbourne Avenue to a six-lane highway from Civic to Dickson. ³²

March 1970: Traffic lights at the corner of Northborne Av and London Cct upgraded. ³³

22 July 1974: The Department of the Capital Territory will modified the traffic lights at the intersection of Northbourne Avenue, Antill Street and the Barton Highway by installing arrow signals. ³⁴

26 July 1974: Arrow signals switched on for traffic turning into Northbourne Avenue from the Barton Highway and Antill Street, bringing the lights into line with most others on Northbourne Avenue. ³⁵

Vernon Circle:

1911: Planning of Vernon Circle by Walter Burley Griffin. ¹⁴

21 July 1960: Vernon Circle name gazetted, named after Walter Liberty Vernon, former New South Wales Government architect, Member of Advisory Board on Federal Capital site in 1909. ³⁶

1960: Work started to extend Northbourne Avenue to City Hill, and the construction of Vernon Circle. ³⁷

6 May 1969: Southbound lanes of Northbourne Avenue extension and Vernon Circle opened to traffic. ³⁸

1 October 1960: Vernon Circle fully opened to traffic. ³⁹

Commonwealth Avenue:

1911: Planning of Commonwealth Avenue by Walter Burley Griffin. ¹⁴

1916: The first Commonwealth Avenue Bridge completed. ⁴⁰

1922: The first Commonwealth Avenue Bridge was damaged by flood. ⁴⁰

1923: The second Commonwealth Avenue Bridge built, using three NSW 'Leychester' type trusses. ⁴⁰ The second bridge was built using materials that had been intended for a bridge near Kings Avenue but not on the current Kings Avenue alignment. ⁴¹

August 1923: Completion of second Commonwealth Avenue bridge, with work started on bridge approaches. ⁴²

1925: The second Commonwealth Avenue Bridge damaged by flood. ⁴⁰

1927: The completion of the third Commonwealth Avenue Bridge was a modification of the previous bridge. It was by a metre and had an added fourth truss. ³⁹

May 1927: The third Commonwealth Avenue Bridge opened to traffic. ⁴¹

April 1929: Bitumen seal laid on the section of Commonwealth Avenue, between the bridge and the hexagon (London Circuit). ⁴³

October 1929: Concrete laid on Commonwealth Avenue for the full length of the two-way road, with the exception of the bitumen strip on the western side. ⁴⁴

1937: Mercury vapour street lights installed on Commonwealth Avenue. ¹⁶

June 1945: Work commenced on repaiting the smaller of the two Commonwealth Avenue bridges. The first stage included the construction of new concrete support pylons, after which a steel support was erected. Concrete decking replaced the old wood surface. ⁴⁵ Work also included widening and the addition of footpaths on each side of the bridge. ⁴⁶

3 April 1946: Reopening of the smaller (Billabong Bridge) Commonwealth Avenue bridge after refurbishment works. ⁴⁷

April 1947: Completion of refurbishment work on the smaller (Billabong Bridge) Commonwealth Avenue bridge. Delays occured due to material shortages, with the bridge reopening to traffic with temporary wooden railings in 1946. These were replaced with steel rails in the 1947 work. ⁴⁸

July 1958: The Department of Works covered the surface of Commonwealth Avenue over Billabong Bridge with bitumen and grit, designed to minimise skidding of vehicles by providing a rough, non-skid surface. ⁴⁹

March 1960: Traffic flow improvements to the intersection of State Circle and Commonwealth Avenue carried out. Work included the construction of a special left turning lane from State Circle into Commonwealth Avenue for northbound traffic. The carriageway of State Circle would be widened to provide additional lanes for both through and turning traffic. ⁵⁰

May 1961: Work begins on the 4th and current Commonwealth Avenue bridge. ⁵¹

13 November 1961: Dismantling began on the Billabong Bridge carrying Commonwealth Avenue over the Molonglo River, for reuse as a temporary structure during the construction of the 4th and current Commonwealth Avenue bridge. ⁵²

15 February 1962: Work started on removal of circular traffic islands at the intersections on Commonwealth Avenue between State Circle and King Edward Terrace. The islands were replaced by smaller elongated islands placed diagonally across the intersections. ⁵³

28 March 1962: The first section of decking on the 4th and current Commonwealth Avenue bridge placed. ⁵⁴

8 March 1963: The old timber truss bridge across Molonglo River used for the last time. The bridge, which coped with Canberra traffic for 41 years, was replaced immediately by a diversion road and later by the Commonwealth Avenue Bridge. The truss bridge was dismantled to enable the construction of the approach embankment for the new bridge. ⁵⁵

6 May 1963: Demolition of old Commonwealth Avenue bridge commenced. ⁵⁶

10 September 1963: Eastern side of Commonwealth Avenue bridge opened to traffic at 6 am. This carried traffic in borth directions to allow completion of the western side. ⁵⁷

1 November 1963: Western side of Commonwealth Avenue bridge opened to traffic. ⁵⁸

November 1963: The fourth Commonwealth Avenue Bridge opened to traffic. ⁵⁹

1963: The fourth and current high-level concrete Commonwealth Avenue Bridge completed. ³⁹

January 1965: Installation of emergency help phones on Commonwealth Avenue bridge. ⁶⁰

1965: Grade separated interchange constructed at southern end of Commonwealth Avenue bridge. ⁶¹

1 October 1965: Grade separated interchange at southern end of Commonwealth Avenue bridge opened to traffic. The interchange was designed to relieve traffic congestion from vehicles turning into Commonwealth Avenue from the Parliamentary Triangle. ⁶²

5 June 1969: Northbound bridge over Parkes Way opened to traffic. ⁶³

October 1969: Installation of 12 160 feet high street lights at the Commonwealth Avenue and Parkes Way interchange. ⁶⁴

August 1972: Permanent traffic counters using similar pads to traffic lights installed just north of Commonwealth Avenue bridge. ⁶⁵

4 June 1982: Commonwealth Avenue name gazetted, ⁶⁶

July 1984: Construction of ramp from Commonwealth Avenue to Parliament House. ⁶⁷

State Circle:

20 September 1928: State Circle name gazetted, ⁶⁸

1937: Mercury vapour street lights installed on State Circle. ¹⁶

1958: Completion of full circle as per original Canberra plans of State Circle. The work was for single carriageway which could later be converted to dual carriageway. ⁶⁹

1959: Kerb and guttering for traffic islands constructed and laying of asphalt surface on State Circle. Landscaping of traffic islands also undertaken. ⁷⁰

March 1960: Traffic flow improvements to the intersection of State Circle and Commonwealth Avenue carried out. Work included the construction of a special left turning lane from State Circle into Commonwealth Avenue for northbound traffic. The carriageway of State Circle would be widened to provide additional lanes for both through and turning traffic. ⁷¹

1968: Widening of State Circle between Adelaide Avenue and Commonwealth Avenue. ⁷²

9 April 1969: Adelaide Avenue and State Circle ramp opened to traffic. ⁷³

28 May 1969: Flynn Drive and State Circle junction and remaining Adelaide Avenue to State Circle ramp opened to traffic. ⁷⁴

25 November 1969: State Circle switched to one way traffic. Traffic was made to travel in a clockwise direction until flyovers from Commonwealth Avenue and Adelaide Avenue to Capital Circle were completed. ⁷⁵

24 February 1970: Upgrade of the State Circle and Melbourne Avenue intersection commences. ⁷⁶

7 September 1970: Loops ramps and overpasses connecting State Circle and Adelaide Avenue opened to traffic. ⁷⁷

February 1983: Installation of traffic lights at corner of State Circle and Melbourne Avenue. ⁷⁸

1983: Work begins on alterations to State Circle to connect and improve traffic flow as part of the construction of Parliament House. ⁷⁹

September 1983: Bridges over State Circle to connect with Parliament House take shape. ⁸⁰

4 March 1987: Work begins on reconstructing State Circle between Brisbane and Kings Avenues in association with construction of Parliament House. ⁸¹

29 September 1987: State Circle re-opened to traffic following completion of upgrade works associated with Parliament House, between Flynn Drive and Canberra Avenue. ⁸²

Capital Circle:

3 August 1971: Capital Circle opened to traffic. ⁸³

December 1971: Work on improving the camber of Capital Circle at its junction with Commonwealth Avenue. ⁸⁴

11 March 1974: Line marking to separate traffic into 2 lanes on Capital Circle commenced. ⁸⁵

4 June 1982: Capital Circle name gazetted. ⁸⁶

1983: Widening of Capital Circle from 3 to 4 lanes and lowered by around 2 metres between Canberra Avenue and Adelaide Avenue. ⁸⁷

1984: Construction of tunnel / land bridge on Capital Circle. ⁸⁸

October 1984: The on and off ramps from Kings Avenue to Capital Circle closed permanently. ⁸⁹

14 October 1986: Capital Circle tunnel opened for inspection by guided tour as part of Professional Engineers Week. ⁹⁰

11 December 1986: The $5.5 million Capital Circle tunnel officially opened to traffic by the Minister For Territories, Mr Scholes. ⁹¹

Canberra Avenue:

20 September 1928: Canberra Avenue name gazetted, ⁹² Canberra Avenue was originally called Wellington Avenue. When Griffin drew up his plans in 1912, there was still some optimism that New Zealand might join the Federation of Australia. ⁹³

27 February 1952: The carriageways of Canberra Avenue converted to one way in each direction. ⁹⁴

15 May 1953: The first phase in the development of a two-lane divided highway to Queanbeyan started when work began on a two-mile road from Jerrabomberra Creek to serve the then new industrial area at and area known then as Molonglo. The overall scheme for straightening the curve near Molonglo siding involves the extension of Canberra Avenue in a straight line through a saddle in the hills, rejoining the existing route near Harman Naval Base. ⁹⁵

February 1962: Reconstruction of the intersection at Geelong Street and Canberra Avenue, Fyshwick commenced with the widening of the pavement area and the erection of a traffic island. ⁹⁶

1965: Completion and opening of bridge over Jerrabomberra Creek. The bridge was constructed in conjunction with the development of a second carriageway of Canberra Avenue between Hume Place and Fyshwick. When the second carriageway and the bridge were completed the southern carriageway was closed temporarily to allow its bridge to be reconditioned. ⁹⁷

Priority Road signage installed on Canberra Avenue between State Circle and Hume Place. ⁹⁸

21 December 1965: The second carriageway of Canherra Avenue between Hume Circle and Geelong Street opened to traffic. It included the then newly completed bridge over Jerrabomberra Creek and intersections with Nyrang and Ipswich Streets. ⁹⁹

20 September 1968: Traffic lights at the corner of Canberra Avenue, Ipswich Street and Hindmarsh Drive (now Monaro Highway interchange) switched on. ¹⁰⁰

1976: Work commenced on duplication of Canberra Avenue between Fyshwick and Canberra. ¹⁰¹

30 July 1976: The first stage of the duplication of Canberra Avenue between Fyshwick and the NSW border opened to traffic. ¹⁰²

9 May 1977: New route between Canberra and West Queanbeyan opened to traffic. It runs from the Queanbeyan side of HMAS Harman, crossed the Queanbeyan-Cooma Railway and joined with Kendall Avenue in Queanbeyan. ¹⁰³

16 August 1979: Work commenced on realignment and installation of traffic lights at the junction with Captain Cook Crescent and Canberra Avenue. ¹⁰⁴

16 April 1982: The NSW section of Canberra Avenue, linking Canberra Avenue from Kendall Avenue to Monaro Street in Queanbeyan opened by the then NSW Commissioner for Roads, Mr Bruce Loder. ¹⁰⁵

February 1988: Work starts on Eastern Parkway (Monaro Highway extension), thus beginning relocation of Hindmarsh Drive and Canberra Avenue junction and construction of interchange at Fyshwick. ¹⁰⁶

22 November 1989: Opening of interchange of Canberra Avenue, Ipswich Street and Monaro Highway at Fyshwick. This also included the rerouting of NR23 between Sturt Avenue at the interchange. ¹⁰⁷

Hume Place (Hume Circle):

20 September 1928: Hume Place name gazetted (named after Australian Explorer, Hamilton Hume). ¹⁰⁸

March 1960: Work commenced on the roundabout at Hume Circle. Work included the extension of the eastern lane of Wentworth Avenue from Cunningham Street. ¹⁰⁹

December 1960: Hume Circle roundabout opened to traffic. ¹¹⁰

Monaro Highway (Cooma Road):

October 1958: Cooma Road renamed Monaro Highway. This meant the route had a single name between Canberra and the Victorian border. ¹¹¹

1964: Channelisation works at the corner of Monaro Hwy and Jerrabomberra Av after representations by a local petition group. ¹¹²

August 1967: The section of the Monaro Highway within in the ACT was the first road in the Territory in which a speed of more than 50 MPH is permitted. The Department of the Interior announced the new limit would be 60 MPH. ¹¹³

February 1972: Speed limit reduced from 40 MPH to 35 MPH approaching the junction with Hindmarsh Drive. ¹¹⁴

December 1982: Completion of reconstruction of 2.5 km of Monaro Hwy between Johnson Dr and the ACT-NSW Border. The work included a new 2-lane road with overtaking lane and a new bridge across Tuggeranong Creek, which replaced a narrow bridge. ¹¹⁵

February 1988: Work started on Eastern Parkway project (Monaro Hwy) with the relocation of Hindmarsh Dr between Jerrabomberra Av and Canberra Av to allow construction of interchange and highway at Canberra Av / Ipswich St junction. ¹¹⁸

22 November 1989: Opening of interchange of Canberra Avenue, Ipswich Street and Monaro Highway at Fyshwick. This also included the rerouting of NR23 between Sturt Avenue at the interchange. ¹¹⁹

11 November 1992: Monaro Highway name gazetted. ¹²⁰

March 2011: Work started on duplicating Monaro Hwy bridge over Canberra Av. ¹²¹

August 2012: Work completed on duplicating Monaro Hwy bridge over Canberra Av. Work included construction of a new southbound carriageway and pavement overlay of the existing Northbound carriageway, construction of two Super T Girder bridges over rail and a cast insitu box girder bridge over Canberra Avenue, installation of bridge safety screens for the bridges over Canberra Avenue, 150 metre reinforced earth retaining wall, the demolition of an existing railway over bridge, modification to an existing reinforced earth retaining wall and relocation of a 1283 millimetre diameter bulk watermain supply across Ipswich Street. The upgrade was the final link in the duplication of the Monaro Highway. ¹²¹

2019: B23 retired and replaced by A23 between Fyshwick and Williamsdale. ¹²²

Ginns Gap To Williamsdale

Advance Directional Sign:

ACT designed AD sign at Ginns Gap on the NSW side of the border approaching the interchange for Majura Pkwy (M23) and Horse Park Drive, February 2016.

Image © Paul Rands

Reassurance Directional Sign:

Distance sign on Federal Hwy (A23) at Watson, August 2016.

Image © Paul Rands

Reassurance Directional Sign:

Distance sign on Canberra Av (A23) at Barton, November 2016.

Image © Paul Rands

Advance Directional Sign:

AD sign on Monaro Hwy (A23) at Hume approaching the roundabout with Isabella Dr, November 2014. This was the first alphanumeric sign installed in the ACT. B23 is a remnant from initial alphanumeric signposting and at August 2020 still remained in situ.

Image © Todd Milton

Isabella Drive:

ID sign at the roundabout of Monaro Hwy (A23) and Isabella Dr at Gilmore, April 2020.

Image © Paul Rands

Williamsdale To Ginns Gap

Isabella Drive:

ID sign at the roundabout of Monaro Hwy (A23) and Isabella Dr at Gilmore, April 2020.

Image © Paul Rands