Thanks for all the interesting and insightful replies. To summarize:
• Call 911 and give precise information as to position and conditions
• Assess the situation against your capabilities
• If you think you can help, park your vehicle out of harm’s way (downstream, if possible)
• Maintain situational awareness, protect yourself so you don’t become another victim
• Render aid as you know how, but first do no harm.
• When the pros arrive do what they say and leave when asked

Also, just so I don’t leave anyone with the wrong impression, I am not a FR wannabe. I don’t gawk at fires or accident scenes, don’t chase ambulances or firetrucks. I carry a scanner because I want to avoid accident scenes at all cost (I drive 500-600 miles a week, the last thing I want is to get caught up in more traffic). I let the pros do what they do and stay the heck out of their way when I can. I carry small personal strobe lights so I can be seen when changing a tire on the side of the road. (I will purchase some safety vests for all the cars, that’s a darn good idea.) Carrying the other gear is just being prepared.

But I don’t think I should shirk from helping out when a need arises. I will plan to get the training recommended and I will keep all the info from your replies somewhere in my brain. Hopefully it will pop up if and when the time comes.

Thanks folks, good conversation.

Andy