I've seen HOLD ON! billboards in the Chicago area, one of which confused my son a bit. It is on the southern/eastern end of the Tri-State Tollway, but what was confusing to my son was it is pointing towards the traffic driving away from the Indiana Tollroad, and the Ohio Turnpike, and was, in fact, readable by drivers heading in the direction of SFGA.
I explained to my son this is "intervention", as in: Do you REALLY want to go to Great America, when the GOOD stuff is the OTHER direction?
BTW, CP seems to be getting more national (or, at least, "super-regional") with its advertising. The May/June AAA magazine had a full-page CP ad on the inside front cover.
(And, interestingly, the story in this issue about Midwest theme parks began with a full-page aerial photo of the Hotel Breakers, with MF rising in the background.)
As CF adds to its corporate collection of parks, I'm sure we'll be seeing more national advertising; and perhaps some with two or more parks featured in a single large-regional campaign.