This is a niche underneath two giants, but it's a sheltered niche. Google and Bing can't copy them without producing strange side effects for their normal users who make typos and copy/paste material into the search box. A slight degradation of service for normal users (who don't expect /map or /time to limit them to a single web site) is much worse than allowing a relatively tiny competitor to have an edge in features.
Google does this with name:value pairs, like site:yahoo.com or format:PDF. You are concentrating on syntax here rather than semantics: the same thing could be accomplished with the (poorly named) "slash" tag, letting users do slash:map, slash:time, etc.; obviously, you would then want to restructure the space of tags to make more sense.
I think people understand that text affects their search and punctuation (usually) doesn't. The "site" and "format" keys are at least self-describing in a way that "slash" isn't.
