Possibilities include rim out of balance, thrown belt in the tire, bad tie rods, bad ball joint, bad struts, or a bad steering rack. Any tire and alignment shop should be able to identify which. Most don't charge for a check and estimate. Jack it up and grab the sides of the tire. Can you wiggle it back an forth? Grab the top and bottom, can you shift it a bit? Side to side tends to be tie rod, bottom shift tends to be ball joint.