Now you're gonna make me reach DEEP into the memory banks
I don't <think> that's properly Hilliard, but you're probably looking at Buckeye Yard. The two roads that I know cross over it are Fisher and Trabue. Trabue is where the yard entrance is, and gives a good view over the hump leads.
Your map probably shows two lines moving on a diagonal from NW to SE, at the north end of the yard. These are the Pennsy Panhandle and the NYC T&OC. The Panhandle is really just a way for the Ohio Central to get into Buckeye Yard anymore, as the line is abandoned across Ohio. The T&OC is owned by CSX going north and NS going south. Neither line is particularly busy. Most Buckeye traffic appeared to head south out of the yard to connect with the E-W NYC line to Springfield and Cincinnatti.
I didn't spend much time on the north end, even though I used to work out of Hilliard, so I don't know of any good places to see action. When I worked south of I270 and 70, I used to see some local freights periodically along the former NYC but the best view was from one of the bridges that crossed the hump leads. Don't remember where you could park and sit.
Your best bet for Cowlumbus action is still Scioto Jct. - see my earlier post in this section. Cheers!