can't really tell how steep it is, but two things that come to mind are to cut a 2' wide slot in your asphalt in front of the garage and make a "V" shaped notch to catch the water, then have it blacktopped. The negative of course is the bump going into your garage. The better solution (a little more expensive), is to cut a notch in front of the garage to act as a drain, and concrete the inside of it to prevent wash out. You'll want to incorporate a ledge on either side (across the short distance of the trench - not long ways) for a grate to rest on. A metal fab shop can make the grate for you out of grate material or metal pipe with welded connectors to keep it in place. You may have seen this used to keep catlle and horses from getting out through a driveway opening in a fence line.