Depending where the driver is going to,does the driver have to come in on the A340.
AP7 is quicker but has tolls or there is the Falset rd about 15 mins longer but toll free bringing you in at Mora then the C12 to Tortosa

If the driver has to go into Reus itself, it becomes a bit more complicated but if he just wants to go from the airport onto the N340 going south, it';s a bit more straightforward.
On leaving the airport at it's boundary, turn right and follow the narrow country road for a short distance to a big overpass roundabout.  Take the third exit.  Continue along the dual carriagway and he'll see some blue signs above.  The right hand one indicates the AP7 and the airport.  The left hand one indicates T11 Tarragona.  Go straight on here.  He will pass over the AP7.  A bit further on there are three more blue signs.  The right hand one indicates 15A, A7, Castello, valencia.  Turn off here.  The A7 becomes the N340.