See? That's what I have been wondering too. I have always thought of freeway is a controlled-access highway, where one is "free" to move without traffic lights. Perhaps I should have said tolled highway. But then, what is the difference between a freeway and a highway?
And I am not too sure how the $5.76 was calculated. If it follows the same patterns as other express lanes in the area, then I am guessing the rate varies depending on the time of day and the number of traffic.
Freeways are like you said - controlled access via on and off ramps with no stop signs or traffic lights. Highways are allowed to have traffic lights and stop signs but will normally have much fewer intersections then normal city/surface streets, and usually have a higher speed limit as a result. Tollways are similar in construction to freeways in that there are normally no intersections, and the only intentional stoppage is toll booths. Though now toll by photo and transponder is a lot more common.