I've just downloaded the latest SimpleStreets and those files aren't there. That means one thing: Someone (who I now wish to fling rather vivid words most unsuitable for this forum at
) has decided it would be an
excellent idea to modify SimpleStreets content for their map and then distribute it
in the same folder as the real SimpleStreets content. Whoever did that is a complete arsehole - doing that makes searching for such content
literally impossible, because the only information to go on (the folder they're in) is utterly useless. For the ease of not having to copy a few files to a new folder, they've made misery for anyone who happens to need these files but doesn't have their map already.
So, the only advice I can give: Somewhere out there there is (or was, who knows) a map whose author created these splines. You'll need that map or another that happens to distribute these files with it to get them. I have
no idea what map that might be and the only way to find out would be to download maps until you get them... unless someone happens to have them and would be kind enough to give them to you (of course, uploading them is then a moral dilemma: with no way to find out who made them, there's no way to know if redistribution is allowed or not.
)