Carol Reed: One really needs to know the shape you are routing here, but if it is a rabbet cut, start your cut 1/2" from the end and make the cut. Then go back and finish the last half-inch from the finished cut to the end of the board. If it is a dado, you will get some "blowout," but it shouldn't be objectionable unless your bit is hopelessly dull. A better bit would be an up-spiral bit. It produces a shearing type cut that leaves less "blowout."

Richard Jones: Try scribing a marking gauge line at the depth and width of the cut. This breaks the fibers and helps chips break out cleanly. You might also be approaching the beginning of the cut aggressively, and a slower initial approach could help.