The folks at the SARTRE road train project have issued an update one year into their 3 year project. This is an EU-initiated project to build convoy technology, where a professional lead driver in a truck or bus is followed by a convoy of closely packed cars which automatically follow based on radio communications (and other signals) with the lead. They have released a new video on their progress from Volvo.

I have written before about the issues involved in this project and many of them remain. It's the easiest way to get a robocar on the highway, but comes with a particularly high risk if it fails -- and failure in the earliest stages of robocar projects is very likely.

In the video, some interesting elements include:

• The building of a simulator to test driver attitudes and reactions. Generally quite positive, in that people are happy to trust the driving to the system and the lead driver. This will change a bit in a real car, since a simulator can only do so much.
• The imagine people eating, drinking, listening to music and reading while in the convoys, but they don't talk about the elephant in the car: sleeping. People doing anything else can quickly take the controls in a problem, but sleepers may not. And there's also that act that we metaphorically call "sleeping together."
• Their simulations depict cars leaving the convoy from the middle. However, in this situation it seems you can't give them too much brake-accelerator control for the difficult task of changing lanes when you are just a few feet from the cars in front and back of you. You must maintain the speed of the train until you have fully left its lane, but that means you can't do the usual task of changing speed as you enter your new lane. Exit from the trains will need some work. (There are suggestions in the comments that make sense.)
• They expect to have to make legal changes to allow this. However, since it's an EU initiated project, they have a leg-up on that. This might pave the way for more robocar-friendly laws in Europe.
• While they plan to do a live test by 2012, they are much more cautious on predicting when the trains might be common on the roads.
• They do speculate if a simple robocar function for "stop and go" traffic, which is able to follow the car in front of you at lower speeds, might come first. Indeed, this is pretty easy, and not much more than a smarter version of existing auto-follow cruise control with steering and lane-following added.
• Their main pitch is environmental, as drafting should save decent fuel. However, I think most people will be interested in the time saving, and I'll be interested in how the public accepts it.