Adelaide - Crafers Highway Shorter, Faster, Safer: Riding the Soon to be Completed Adelaide-Crafers Highway with Keith Conlon

The Old Tollgate at Glen Osmond has stood guarding the entrance to the interstate highway through the Adelaide Hills since 1841. It now signals the start of the biggest revolution on the route since the bullockies started their treks up the ridges to Eagle on the Hill and over the ranges.

It's currently Highway No. One's worst entrance to a capital city, and it's about to become the best. The federally funded Adelaide-Crafers Highway Project is non visibly approaching completion.

The complex Glen Osmond intersection is undergoing radical surgery and with extensive widening and shifting of its three suburban arteries which fan out from the highway as it emerges from the foothills. The historic Birksgate loses ground for a new down-track lane and gains a bluestone wall, while the Carmelite Convent similarly sheds territory and hosts a high limestone wall.

A 'showcase' setting is being designed, complete with contemporary sculpture, and so the traditional stone building materials of old Adelaide will be joined by imagery promoting its twentieth century city of the arts reputation.

Within a kilometre of entering the hills, the first major works of this $140 million project are obvious. A sweeping bend of the old road is buried beneath thousands of tonnes of fill, raising the level a full highway light pole higher. Next, the graceful 43m single span Mt Osmond interchange bridge swings overhead. Major blasting has taken out the southern side of the gully to accommodate the new three lane down-track, and a curving entrance way form the dress circle suburb above.

At the infamous Devil's Elbow, the revolution really begins in earnest. Only local traffic will swing 180 degrees, through an underpass, and grind up the old bullock track. The new highway sweeps instead up the gully. That's the first great difference. The new route keeps to the gullies, rather than scaling the ridges. That's where the 'star' of the project becomes vital. The twin tunnels cut directly under Eagle on the Hill and the old road, thereby cutting about two kilometres off the hills journey. That, combined with three lanes each way, will cut journey time and vehicle roll-overs on this notorious stretch of the main Adelaide to Melbourne road.

The new tunnels are now fully concrete lined, and taking on board myriad cables and electronic paraphernalia. They will feature technology that wasn't invented when the last tunnel was completed anywhere.

The 'intelligent' tunnels feature 'sniffer' fans monitoring carbon monoxide levels, motion reading cameras that detect abnormal traffic slowdowns, and cabling to keep mobile phones and radio alive during the half kilometre run under the ridge.

Last September, I rode one of the early trucks through, and it was a precursor of the smooth curving downward drive that will be all over in twenty seconds once the project opens. The first tunnel played a vital construction role too, with seven thousand truckloads of rubble coming from the top of the project to fill the gullies on the lower half.

First timers to Adelaide will gain a new first-sighting of the suburban plains as the route flows through a hidden gully. It was hidden by deep thick shrub, at least, until the construction engineers began shifting hill sides. Just before the highway reaches the summit of its climb and the hills village of Crafers just over the crest, it joins the old alignment again. The Measdays Hill section is almost unrecognisable, however, with a new canyon for cars dug. It is about three or four stories lower in building terms. It is a strange sensation to stand on the old road surface on the edge of the project as the highway rolls over a saddle of the Mt. Lofty Ranges high up near its pinnacle. The new highway lanes are a cliff-face below. The Crafers summit has been shaved substantially.

That is perhaps the most visible sign of the other great difference between the old and the new road routes. By taking the gullies option, coming up through a tunnel, and shaving the top off the final obstacle, the designers have revolutionised the gradient. It will soon be 6 1/4 go all the way from the Tollgate to the top. That translates into a comfortable ride in top gear for most cars, and most importantly, most interstate trucks will maintain speed close to the limit.

In the meantime, the roll-overs are still occurring - the crash rate is six times that of the freeway beyond Crafers - and the endless diversions on the old road are making hills commuters very keen to know when their magic carpet ride begins.

After all, they've waited a long time. The project was enrooted more than a decade ago. At last, in 1995, it gained federal funding as a National Highway project. The SA Government's Transport SA is managing the project, and the construction joint venture sees Macmation and Concrete Constructions now looking at a completion date.

With winter descending, and 73000 tonnes of top road surface still to lay, they are understandably a little reluctant to name the day. All the parties are happy to admit, though, that by the contract completion date of April 2000, the highway will be well travelled.

The commuters and the contractors need a mild winter if the planned completion festivities in the tunnels are going to turn into Christmas parties. In the meantime, the new route is non much in evidence, and a drive off peak up the old road takes you on the nineteenth century trail, with extensive glimpses of the twenty first century entry to Adelaide.

For more info you can visit the Transport SA web site at http://www.transport.sa.gov.au/adelcraf