If you park on a side street you are on the correct side of the fence.
You are looking for a plastic peanut butter jar, about 6" tall and 4" in diameter. You must drive off the highway by an exit ramp to get to ground zero. You might have more trouble trying to get your car close than you will finding the cache. I think if you exit 44 westbound a series of 4 consecutive left turns (don't get back on the highway for turn 2) gets you there. If you exit eastbound it is only 3 consecutive left turns. You cannot park on the highway and get this. A fence is between the highway and where this cache is. No need to climb a fence if you come from the side street.
Good luck, and happy caching.
Congratualtions and FTF honors to cameliaprescott