Couple of questions. How are they powered (solar?). If someone were to get a ticket and protest that the sign changed after they had parked, what process is in place to allow them to review the content record for that sign?

They are powered with solar. The technology doesn't change the other problem - they changed the signs previously by updating the content manually (replacing the plates). I'm guessing they have this sorted out.

Talking about value, what is the price difference between a regular road sign and a e-paper version?

How many employees could be hired changing the physical road signs given the price difference?

When it comes to deploying outdoor signs the price of a sign is the least of your worries when it comes to TCO. It's more about how much does it cost to deploy and how much does it cost to manage the signs. Digital signs also give you the ability to update information more often.

Given the positive feedback from the end customer and Mercury Innovation (http://www.mercuryinnovation.com.au/) that took our platform and built the traffic sign (we're not the ones selling the end product) I'd say that TCO is in favor of e-paper traffic signs.

Disclaimer: I work for Visionect

Since you work for Visionect and appear to be astroturfing on Hacker News, it would be nice to have a second opinion.