Mount Barker Road was once the main road fromAdelaide through theAdelaide Hills toMount Barker on the eastern slopes of theMount Lofty Ranges. The main route has now been replaced, or subsumed into, theSouth Eastern Freeway, but two sections of it remain, and are still classified as state roads.^[4]

Mount Barker Road Adelaide Road South Australia
Mount Barker Road looking northwest in Aldgate
West end East end
Coordinates	34°58′01″S138°40′05″E / 34.966848°S 138.668172°E /-34.966848; 138.668172 (West end) 35°03′18″S138°51′11″E / 35.055059°S 138.853126°E /-35.055059; 138.853126 (East end)
General information
Type	Road
Length	24.0 km (15 mi)[1][2]
Route number(s)	(1998–present) (Stirling–Aldgate) (1998–present) (Verdun–Hahndorf) (1998–present) (Totness–Mount Barker)
Former route number	National Highway A1(1998–2000) National Highway 1(1974–1998) National Route 1(1955–1974) (Glen Osmond–Crafers) National Route 1(1955–1972) (Stirling–Verdun) National Route 1(1955–1974) (Verdun–Totness)
Major junctions
Mount Barker Road (West)
West end	South Eastern Freeway Leawood Gardens, Adelaide
East end	South Eastern Freeway Crafers West, Adelaide
Mount Barker Road (East)
West end	South Eastern Freeway Stirling, Adelaide
	Strathalbyn Road Onkaparinga Valley Road Echunga Road Old Princes Highway
East end	Wellington Road Mount Barker, South Australia
Location(s)
Region	Adelaide Hills[3]
Major suburbs	Eagle On The Hill,Crafers,Stirling,Aldgate,Bridgewater,Verdun,Hahndorf

A vestigial portion of Mount Barker Road exists through the "Old Toll Gate" atGlen Osmond, but has completely subsumed into theSouth Eastern Freeway as far as the Devil's Elbow, where a surviving western alignment of the road turns a sharp hairpin and has a winding uphill throughEagle On The Hill and rejoins South Eastern Freeway near Measday's Hill inCrafers West.^[4]

The eastern portion of Mount Barker Road resumes from the freeway's Stirling exit, passing through the main shopping strips ofStirling andAldgate^[4] as State Route B33. From Aldgate, Route B33 continues onStrathalbyn Road, while Mount Barker Road follows the railway line as Tourist Route 57 to Bridgewater and under the freeway at Verdun where it joins State Route B34 (fromOnkaparinga Valley Road) for a little over 3 kilometres (1.9 mi) throughHahndorf. At the south end of Hahndorf route B34 turns under the freeway towardsEchunga and Mount Barker Road continues on the north side to the Mount Barker Interchange atTotness, where it changes name to Adelaide Road, and eventually ends at Mount Barker.^[4]

Mount Barker Road served as an early alignment ofPrinces Highway some time after it was first declared in South Australia in February 1922,^[5] initially defined along Mount Barker Road and the route via now known asStrathalbyn Road from Adelaide viaAldgate,Mylor,Macclesfield,Strathalbyn,Langhorne Creek, crossing the Murray River atWellington and then continuing along the present route beyondMeningie,^[6] By 1928, the route was re-aligned to run further along Mount Barker Road throughMount Barker, and alongWellington Road viaWistow andWoodchester to Langhorne Creek,^[7] although by 1935 this alignment was changed to run viaNairne,Kanmantoo,Murray Bridge andTailem Bend (along what is now known as theOld Princes Highway).^[8]

Princes Highway functioned as Adelaide's major south-eastern approach and was heavily trafficked; government plans to upgrade this route weaving through the Adelaide Hills had begun by the early 1960s. Initial sections of the road project that eventually became theSouth Eastern Freeway commenced in December 1965, along a 2 km section from Measday's Hill toStirling: the eastbound carriageway was opened to traffic in 1967, and the section was fully completed in 1969 when the remaining carriageway and the Crafers Interchange became fully operational. The next stage extended the freeway east throughBridgewater toVerdun and opened in 1972, and fromVerdun toMount Barker in 1974, completely replacing Princes Highway – renamed back toMount Barker Road – as the main route between Mount Barker and Crafers. As this was part ofHighway 1, the route was progressively re-aligned along the freeway as sections of it opened. Mount Barker Road today remains as the main street of Stirling, continuing toAldgate,Bridgewater, under the freeway atVerdun, then throughHahndorf to end near the Mount Barker interchange of the freeway. The road continues south over the interchange asAdelaide Road (reflecting the reverse journey) to terminate in Mount Barker.

The last part of the South Eastern Freeway to be built reconstructed the Adelaide end of Mount Barker Road including a grade-separated intersection at Mount Osmond Road. It replaced the infamousDevil's Elbow hairpin with a partial interchange. The new freeway passes through theHeysen Tunnels and rejoins the former alignment the other side of a steep ridge. Mount Barker Road itself climbs over and around the ridge. Since the four-lane dual carriageway is no longer required, part of the uphill side has been replaced with a bike path used as part of a popular cycling route toMount Lofty and all motor traffic uses the former downhill carriageway. The section between the Measdays interchange andCrafers was also completely replaced by the freeway being built on the same alignment at a lower level in a deep cutting.^[9]

In 1841 a special Act "... for the making, and maintaining the Great Eastern Road" was passed, and construction of the first section from Glen Osmond to Crafers begun at public expense. It was soon realised that this undertaking would be hugely expensive, so a novel (for the day) plan was hatched to relieve the Government of all expense by vesting the management of the road in a private company. The successful tenderer would have the responsibility of completing and maintaining the road, and have the right to levy tolls on users of the road. As this was the only route to and from the burgeoning agricultural districts aroundMount Barker, not to mention all road traffic to the eastern colonies, this had all the hallmarks of a great money-maker. The author ofThe History and Topology of Glen Osmond, Under-TreasurerTom Gill, no stranger to public finances, described this a 'curiosity in road legislation'.

A toll gate and accommodation for the gate-keeper were erected and one Samuel Selby appointed keeper of the toll-bar, which was to be staffed 24 hours, seven days a week. The tolls levied were:

For every coach, chariot, chaise, gig, hearse, caravan, or other carriage, and every cart, wagon, dray, or other vehicle, if drawn by one horse or two bullocks, 1/.

'For 'such carriage or vehicle' drawn by two horses or four bullocks, 1/6; by four horses or six bullocks, 2/; by six or more horses, or eight or more' bullocks, 3/;

by one pony, mule, or ass not exceeding 13 hands high, 6d.; by two or more such ponies,' mules, or asses, 1/; for every saddle or led horse, mule, or ass, 6d.; for horses, mules, asses, oxen, cows, or other neat cattle driven, per head 1d.; and for sheep, lambs, calves, dogs, swine, or goats driven, each ½d.

Only one full toll in any one day might be demanded for any animal or vehicle, except stage coaches or carriages plying for hire.

Exempt from payment were: the Governor, survey, and police, also agricultural produce not bought or sold, but going to be sold or disposed of, also persons travelling to and from Divine Service on Sundays.

The tolls were vexatious and led to a great deal of ill-feeling and were abolished in 1847 by the Legislative Council on the motion ofSamuel Davenport. The company failed to reap the rewards anticipated, partly on account of the increased cost of labour as a result of the exodus of able-bodied men to the Victorian goldfields.^[10]

The octagonal toll-house, much restored, still stands atGlen Osmond, between the up and down tracks at the start of the Mount Barker Road, now the South Eastern Freeway.