An increase in either of these physiological components (cardiac output or TPR) causes a rise in the mean arterial pressure. Vasodilation works to decrease TPR and blood pressure through relaxation of smooth muscle cells in the tunica media layer of large arteries and smaller arterioles.
Contractors' prices for 2-4 hours with heavy equipment removing a small area of concrete (such as a 8x10-foot patio 4-8 inches thick) start around $250-$550 and go up. Removing an average driveway is $1,000-$2,500 and up, particularly if it's reinforced concrete. Prices vary considerably by region.
600 x $3-$4 = $1,800-$2,400 (estimated asphalt driveway cost). At that approximate cost, a driveway contractor will dig out 4-6 inches of whatever you already have in place, replace it with clean driveway gravel and grade it to a level and compacted surface.