Is this a Myth ?

[issatree]

Hi All,
I've heard about this many years ago.

If you go around Australia, by road, say leaving Geelong, heading up the Sydney way.
I'm told that it is 128 Kilometres SHORTER, than going over the Perth way.

The reason is :
That you are on the inside, & not on the out side of the Road.

What do you know about it.

[Ashore]

You can work out the difference mathematically: take an average distance between the lanes (3 metres) and the total road distance around Australia, turned that into a circle, and then work out the difference in circumference between the bigger and smaller circles. One suggestion is that it should be 2pi X (separation of the lanes) so say 3m between the lane centres - that's about 19m.
I love Google :2tsup:

[joe greiner]

Old wine in a new bottle.

Engineers were building a railroad around the equator. Revised plans required it to be raised 3m. How much extra track do they need? Same as Ashore: about 19m.

However, if the roadways in the two directions are divided sufficiently, there could be enough discrepancy to increase the difference. I doubt 128km though.

Cheers,
Joe

[_fly_]

I do know that if I go from Dandenong to Lakes Entrance during the day and stick to my lane its 296 km. If I go in the middle of the night and cut the corners (using both lanes) its only 294. Thats 2km less on a 3 hr journey.

[Geoff Dean]

Hi All,
I've heard about this many years ago.

If you go around Australia, by road, say leaving Geelong, heading up the Sydney way.
I'm told that it is 128 Kilometres SHORTER, than going over the Perth way.

The reason is :
That you are on the inside, & not on the out side of the Road.

What do you know about it.

I guess that theory uses the summation that the outer road is always the outer road. What happens when the outside road has an inside radius. (think letter S.)

Possibly it is a bit longer, but I would doubt 128km.

[joe greiner]

The reduction due to the reverse curve (inside) would be compensated by the increase in the other curve. As long as the lanes are locally concentric throughout, the overall perimeter would morph into a circle, and the analysis prevails.

"Locally concentric throughout" is the trigger. I can envision situations where divided highways drastically diverge, but 128km is a whole lot of divergence. Ring roads, e.g. could have very different path lengths for entering and leaving in two directions. Several of these might add up to 128km. YMMV.

Cheers,
Joe

[rsser]

There is a view that it's best to drive around Aus. counterclockwise given the prevailing wind direction across the southern part of the country. Having a tailwind reduces fuel consumption.