Is a roofing delivery truck likely to crack my driveway slab?
Unless your home is a 20 bedroom mansion I would simply tell them to keep that off your driveway period.   You can't tell what load it will take because it depends how packed it still is, what condition it is in and how thick it was poured (and if this was uniformly done).   Often these large trucks will crack driveways in the corners of their pours since the depth in the parts are tapered even by the most reputable companies and can get to 3-4" inches with poor contractors.   

So just don't let them on driveway or make that a risk their insurance will pay for.   I have roofers at sites all the time.   I hardly ever let them on the driveway.   With a crew of 4-5 they can carry the stuff/wheelbarrow/whatever and it is done in 20 mins.   Stay off my driveways, don't break them, don't drop crap from your trucks, don't spit mud everywhere - not my problem.   

If my front lawn is not in great condition and it is dry I tell them to use that.   That is all I offer.   If they have a regular truck then fine.   Even a bobcat I will not let them go up and down the driveway unless they are paying for repairs.   

Bottom line is you paid for a new roof.   Their deal to get shingles to your house.   Not saying to be unreasonable - I try to make things easy for trades to get future discounts but you must use common sense.   There is a good chance that crew suggests pulling truck next to house and then if the owner came out he would yell at them (worried about being liable for damage).   Yes of course a truck that big could damage a good percentage of driveways.   

Addition for dump truck: This depends on size.  I have never had a roofing company use a dump truck at my site.  These are less risk because of wheel sizes but still not letting a full size one on my driveway.   Most roofing companies for a residential house use dump trailers that are a lot less invasive and they are lower to the ground so you can get these really close to house so there isn't a ton of stuff in the gap.  

(FYI this size truck is about the same size the big boxes use to deliver bulk drywall.   The operators of these trucks will not come on your driveway if you request that they do.   Simply they know the chance for damage is high and they would probably be liable and get fired.   That is why they use a forklift.   If there was no risk then these huge companies would be instructing their operators to save time by driving as close as possible - big companies micromanage these processes to make money.)