Concrete driveway

You did not say how thick the concrete would be. I'm figuring 6" thickness which should handle just about anything you'd bring in. Suggest using minimum #4 rebar at 16" ea. way rather than steel mesh - if you are planning to use steel with the fiber mesh mix.
Anyway, 20'x144'x6" = 1440 cu. ft. = 54 cu.yd. A full concrete truck holds 9-10 cu. yds, but be sure that a full truck can drive onto your property without getting stuck - that's a huge weight. You may need to go 1/2 or 3/4 loads - sometimes that's an extra charge, but worth it to get the trucks in there. I like to have an area available that any extra concrete can be dumped into - like a walkway, door stoop, etc.
What's the experience level with the installers? You will need a couple of guys to push concrete into and around the forms, plus a couple to run a level board across the top, bullfloat, etc. The guys pushing the concrete can move to the next form as the others work behind them. I would suggest about 30 minutes between loads to give enough time to get each load concrete placed, but it might need to be a little more depending upon experience.
I would also suggest expansion joints at 18 ft. intervals - that would be 8 expansion joints evenly spaced over the entire length of the driveway. If the sections are 18' apart, that is 20'x18'x6" = 180 cu. ft. = 6.7 yds per section. You can also play with the expansion joint interval a bit to change the cu. yds. needed for each section, but I would not go over 20' on the individual section lengths.