It is too close to Adelaide though you can drive there quicker than any train would which is why bus companies are running a service to the Barossa Valley it is quicker even if the track was completely renewed. The closest piece of Adelaide Suburban Area is Gawler or one of its satellite places. The way things are going here now it would not be long before Roseworthy is part of the greater Adelaide suburban area. It is pretty close to it now actually it will not take long to build between Gawler and Roseworthy.
The slow part of the trip is the actual trip from Adelaide to Gawler as even if you run express you could catch up to a all stations Adelaide Metro stopping train and as you cannot pass it you just run on its red lights from wherever to Gawler, once there you can take the track to Gawler Central and be on your way. Adelaide to Gawler by train takes 55 minutes, then a AM bus trip to Nurioopta takes another 44 minutes. The bus runs every 4 hours though where the train runs every 30 minutes. All up it will take you 2 hours 39 minutes to get there using this method which is the 810/811 bus from Gawler if you actually make the bus connection otherwise you have to spend 4 hours in Gawler sort of stranded there.
But you can drive or take a private bus direct there from Adelaide that takes 54 minutes from Adelaide Bus station CBD so you can see how most would travel, the full bus option is much quicker and enables you to spend a bit more time in the Barossa than the train would ever do. By the time the train reached Gawler you would be in Nurioopta if you had travelled by the bus service from Adelaide.
Like I said it is too close to Adelaide where other competing forms of transport can beat it hands down every time.
Are those operators up there that met the trains still want to do that though, possibly the local Taxi maybe but the bus companies I think would want to run the whole route from Adelaide and so make a decent profit to invest in new buses. They would be more interested in long distance trips and charters, etc rather than running a local pick up and drop type operation. But if it could be done again the longer distance on the bus still wins hands down though. Oh and the buses I am talking about are not Adelaide Metro bone shakers from the metro area but modern type long distance coaches which are used on the Barossa service now. Just under a hour in one of these would be a lot better for most people.
The further the distance the more road will be favorable, if you look at the commuter time travel, the slowest part is closer to Adelaide and then once out of suburbia the bus is sitting 90-100km/h. So unless you are building well aligned 120-140km/h track no.
Adelaide's growth is not Sydney, I'm sure it will happen but it will be along time before the cows need a new home, however should thus happen when ever it happens it justifies returning the line to service with an upgrade.
- Gawler Central to Adelaide is 48min on express service for a distance of 42km, average of 69km/h, eliminate both Gawler central and and call it an even 70km/h from Gawler Central for 47min.
- Gawler Central to Nuriootpa is 77km, so another 35km. Assume an average speed of 70km/h this is 30min for a total trip time of 77mm (1h 17min). Average speed of 70km/h is pretty slow on a line with only 3 stations and likely no passing loop delays or complicated track work and the section from Lyndoch to terminus (20 of the 35km) is actually fairly straight. So I think this is a practical assumption with a half decent track upgrade, ie concrete sleepers and half decent rail.
81km in peak direction and time is similar to above, or as fast as 55min in off-peak. But we all know in peak most commuter rail services are often faster than their road equivalents and in off-peak they are slower.
So Adelaide to Nuriooptia by train off peak, 1:15-20min and by road 55min. Not exactly huge is it. In peak flow and time, they are on par.
Our trip on the BWT was a full day and to be fair I think we were wine toured out by the end. The train was certainly not for everyone and which is why I say it will not return on its own, but rather RPT service with potentially a tourist train option either added to the train or operated separately. RPT does not have to equal an 30min service, there are plenty of examples for similar services in Australia with less.
All those companies that were there before will be there again should the train return, why wouldn't they, they were not there before the BWT? 50-100 people arrive wiling to spend their money, take a guess. Also take a guess how many of us would not have gone if there was no train as I had little interest to sit in just a bus for 8h. Ironically there is probably more opportunity than the BWT had the money to do by exploring additional stop(s) around Jacob's Creek, surprising how many winneries basically have their back door on the railway line when you look. Again I'm not saying you will do a wine tour on solely a train, but its a means to an end.