The speed limit is actually 40mph until you are just north of Cook Road. I was pulled over at 2AM for doing 51mph in what I thought was a 45 and the I told the cop I was going the same speed as the only other vehicle on the road, a van. He said the van was going one mph less than I so he pulled me over. I assumed he was looking for drunks, and I was stone cold sober, returning from Indy following a later flight home. The good news. When I went to pay the ticket, the cop had written it for the wrong date and it was thrown out so I didn't have to pay! Best speeding ticket I ever had. The cops sit at Northrop High School and wait for you to come over the hill that crosses I-69 and catch you on the down hill as you're approaching the intersection of Cook Road.