I had been waiting for a little more discussion before declaring my own position.
The background to the question is a complaint from a customer about a translation done by a colleague of mine. One of the many changes made by the customer, who was not a native speaker, was "prepared" to "willing" in the context indicated.
Although the distinction is subtle, my native intuition tells me that it is there and that "prepared" is preferable in the context.
I feel that "prepared to do something" suggests an underlying mindset, whereas "willing to do something" is a response to a more or less explicit invitation or opportunity to engage in an action. Thus, for example, I would argue that the following are more natural:
- Firefighters are prepared to risk their lives for other people
- Only a few firefighters were willing to go into that inferno.
- He is prepared to abandon every principle for the sake of his career
- He was willing to sacrifice his friendship with Paula for the sake of his career. (The implication being that this circumstance actually arose.)
In terms of the text in hand, we are talking about whether participants would entertain the possibility of texting while driving, not whether they responded to a specific circumstance.
Have I got this right?