West route options
There are four options for HSR through Victoria to the west of Melbourne to the South Australian border and two from there to Adelaide. All routes connect to Tullamarine Airport, Avalon Airport and terminate at Adelaide Airport. Regional residents on or near HSR would have direct access to airports.
The first route from Melbourne is via Ballarat to Bordertown and Adelaide. It is the shortest and quickest at 730 km and around 2½ hours, Melbourne CBD to Adelaide CBD. It would be least cost, except the track into Ballarat is the steepest and hence higher cost with potentially major tunnels and/or viaducts. Ballarat is the largest city on the route with a population of 100,000. It already has a Victorian fast train service (not HSR) to Melbourne. It is the most inland route and so least attractive to potential new settlers than cities nearer the coast and beaches.
The second route is via Geelong to Ararat, on to Bordertown in SA to Adelaide. Ararat is about 215 km from Melbourne, 143 from Geelong, 157 from Bordertown, and 530 from Adelaide, only a little further than option one at 745 km. It is along the “Overland” railway route. Ararat region would become a centre for a new large city, though may be limited by access to water supply. The route is partially closer to the coast than via Ballarat. Geelong is the largest city in Victoria outside Melbourne.
The third option is via Geelong, Hamilton and Mt. Gambier in SA to Adelaide. This is longer than the previous two routes at 801 km, but nearer the coast.
The fourth route is via Geelong, Warrnambool, Mt. Gambier to Adelaide. This is along the coast all the way and is most attractive, but is much longer at 903 km. It would pass through presently dormant volcanic country. This longest route is about as far as Melbourne to Sydney and would take close to 3 hours, half an hour more than the shortest.
Clearly there is a four-way trade-off between attractiveness for a million more people to live in each of two new commuter cities outside Melbourne to the west and Adelaide to the east nearer the coast; the cost of building the longer route; and the less convenient longer trip time, Melbourne to Adelaide; and access to water. It may be a social benefit necessitating State Governments to consider offering inducements to the private Consortium to build a longer track and possibly lose some of its more profitable through passenger custom. Services for commuters are rarely profitable because of higher costs, so prices are higher and volume therefore is constrained, a potential vicious circle of higher price/lower volume, lower volume/higher price. This would be remedied by increasing Melbourne and Adelaide land taxes by a small amount to subsidise commuter fares in return for more liveability.
South Australia route
With Adelaide potentially growing by a million or 100%, it would be desirable to have a new city on the HSR out of Adelaide for distribution of half a million to one million SA growth by 2050. The Bordertown region would be suitable, within 1½ hour drive to the coast and within commuting distance to Adelaide.
The southern Australian population would be 2 m in Adelaide and +8 m in Melbourne, a total of +10 m plus regional populations by 2050 without HSR. This would make the HSR west a viable addition to the east coast system, but it is less so at present. A stronger case may be made after the HSR is in operation between Geelong, Melbourne, Brisbane and the Sunshine Coast. The Victorian east coast route should be built first, then the west from Geelong.
It is unlikely that the HSR west of Geelong to Adelaide could be built privately at present, unless with some government financial assistance and/or with value capture applied to housing above trenches in the main cities and to new cities.
The longer the HSR service to the west is delayed, the more people would settle in Melbourne and Adelaide. It is in the interest of Victoria and South Australia to divert population growth to new cities in the regions between Melbourne and Adelaide soon.