I'm almost certain the same is true for Australia. I'd really like to compare the highway traffic from Adelaide to Perth to either the railway tickets or plane passengers between those cities. And it's a whole lot more than a puny 500Km trip.
For families travelling up/down the East Coast of Australia (between Melbourne, Sydney and Brisbane), a lot of people drive, as unless you're travelling by yourself it's cheaper to drive.
Example, An airline ticket between state capitals will cost about AU$200-400 return per person, and unleaded 91 octane is currently AU$1.56/l in Brisbane, (I'll let you do the maths). Flights to Perth from the East coast return are about AU$600 per person. Add in care hire or taxis at the the other end, and it adds up very quickly, so a lot of people drive.
I personally know a lot of people who drive from Gold Coast to Brisbane each day for work (approx 75-100km ea way depending on where you live). Also the areas in which state capitals have spread/expanded could mean a 100km trip to get from one side to another. For example, in Melbourne, to get from Werribee (far western side) to Frankston (far eastern side) is a 90km trip... Brisbane; Beenleigh to Northlakes is just under 80km, Sydney: Liverpool to French's Forest, 60km. People do these sorts of drives daily... All these examples while demonstrate that current electric vehicles could be used, a lot of people would find inconvenience in doing so. Also, having grown up in Melbourne, my family would do day trips out to different places each weekend, eg Bell's Beach from our home was 100km each way, Venus Bay** (we stayed a lot at a friends beach house over summer holidays) was 180km each way. **Venus Bay 30 years ago was a small holiday location with small beach houses that really catered for people who wanted to go to the beach, go fishing, etc over the summer break for a few weeks at a time. And on comparison to most of my friends from school, most other families did similar... (trips to coast from Melbourne).
PS. Adelaide to Perth according to Google Maps is 2,693km (1,673miles), and not to mention a big f&*king desert between them. The best US orientated example would be Los Angeles, CA to Kansas City, MO. with no cities between...