Hi,
Thanks to all who helped.
We are now in Portugal with our rental car. The toll system has been made more tourist friendly over the years. In stead of several systems and you having to guess which is where. Yes, an electronic transponder can be installed or activated in your car for about 1.84 euro per day, a maximium charge 18.40 euro for rentals of 10 days or more. That is the rental fee for the transponder.
As you approach a toll booth area look for the GREEN slanted V. Go through one of those lanes slowly and it will record your passage. The next time (exiting the road perhaps) the toll both with the slanted V will show how much you will have billed to your charge card when you go to return your car.
Very nice not to have to worry about having correct change or bills that work, or credit cards that will be accepted.
By the way, I got a 18 day rental for $97. Plus 18.40 for the transponder.
wayne iNOBidos