Roundabouts, contrary to your handout, do take more pavement and resources (and are non pervious surfaces that cause water problems), and can end up taking more time than traffic lights. I got stuck exiting i12 in Hammond at the roundabout. I wanted to turn to the left. The roundabout is 2 lanes and small and the through traffic was solid and continuous, there was no way I could enter and merge in, much less get into the inside lane to go left around and continue into Hammond.
Traffic analysis of the roundabouts indicate that they will function well at the locations for which they are proposed.