From the Author
Four routes through the articles
The articles on this site were written one at a time, as questions came up, as research was published and as readers wrote in. Read in order of publication they can look like a series of separate observations. Grouped by subject they turn out to be four conversations, each returning to the same idea from a different direction.
Every article belongs to at least one of the four topics below. Each topic opens with a short introduction explaining what holds that group together, followed by the articles themselves. If you are new to the site, the six principles are the natural place to begin, because the other three topics are all applications of that framework to particular kinds of journey.
Implausible instructions, device failures and the evidence on why the driver must still decide.
How to weigh a suggested route change, and why live traffic is advice rather than instruction.
Couriers, truck drivers and motorhome owners, and the preparation that harder routes require.
The framework itself, the official standards that support it, and why it outlasts the technology.