It is incorrect because "alternate" has nothing to do with "alternatives" at all.
Alternate has to do with a repeating pattern and the action of changing between segments of a pattern.
(It is a verb)
Alternative indicates there are two or more options from which to choose one option...it is a noun.
So they sound similar but are actually 2 completely different words and are not interchangeable.
Incorrect? Yes. But, it was a road sign, so you have a matter of seconds to read it. When reading that very quickly (as you would when driving), it could easily be confused by some as being read as 'find alternative route', which is easy to understand. Or, the sign may not have been big enough for 2 extra letters??
Even used in its adjective form, 'alternate' still would mean 'every other [road]' rather than 'a different [road]' so the usage in this case is indeed incorrect.
Actually it doesn't always mean that.
Alternate can also mean a choice of one or more. I will find the dictionary definitions I found when I'm not on iPhone.
My mistake Pandora - my fault for going on the first set of definitions I found! Alternate *can* be used as an adjective to mean 'substitute' 'used in place of' or 'second or further choice' (although these definitions do seem to be more common in American dictionaries).
In addition to the word on it's own, I found something pretty interesting (well, to me lol) on where the term 'alternate route' came from.
In the US, An alternate route is a route that branches off and then back on to the main/parent route, but not in order to bypass a town/place. There's a cool picture I might put on my fb and link back showing different kids of routes/roads
Even when used as an adjective, in correct English, this use would be incorrect.
The Oxford dictionary recognises that in "North American English" Alternate can be used in this way, but we are not American, and do not speak American English, nor is is "correct".
Bookmarks