The issue is nearly always the same: "unique content." We have some magnificent student projects listed in the ODP, and we've had some pre-teenagers active editing the ODP, so we're used to holding them to the same standards our grandparents follow -- or rather, we recognize the fact that they hold themselves to the highest standards and even help us raise our own standards. That's not an issue.
The prominent information on the site is driving directions to schools -- OK, so you have a database of school addresses, and an interface to mapquest. This is a pretty good basic class project for a web class -- you have your database, back-end accesses to someone else's server, some mapped graphics, etc. The site functionality itself is (so far as I saw) very nicely done. If the point is to learn how to create middleware, I'd give the students high marks and a recommendation.
Weaknesses -- the page layout gives "baroque" a bad name, but hey, it's a web technologies class, not a graphic design class. And bad page layout is no bar to an ODP listing -- it's as good as anything at MSN.com, and I've certainly given far less ambitious and less successful designs an "editor's choice mark." In class, better ambitious than minimalist. (Outside class, you quickly learn the virtues of minimalism. But the more tools you have, the better chance you have of picking the RIGHT minimal tool.)
So far, so good.
The problem is in the actual content creation. That's really all that matters to US as ODP editors, and that's where IMO the site falls down. It's not really a contribution to the sum of human knowledge. It is a (very good) internet project, rather than a (very good) scientific or artistic or humanitarian project published on the internet. It is the latter that we look for.
If those students had gotten together with, say, an honors drama class to create a multimedia version of the Second Shepherd's Tale [mystery play], or with an honors history class to create graphic displays of tabular historical data, or with a local charity to maintain a client database and/or attract donations -- I would have gotten a very different impression, and I'd probably have fallen all over myself to get the site listed.
Now, it's possible that there's something more besides the school driving directions, and the poor usability design of the site kept it hidden. Get the students to do serious site reviews of some of the good sites in common use: the ODP (some of them probably ought to be editing here anyway, man!), Google, ccel.org for the religious ones, Project Gutenberg -- sites that depend for their lifeblood on NOT placing ANY obstacles to repeated, fast access -- teach them minimalism, and ... there will always be a place in the workaday world of custom net software design for them. But it takes more than doing SOMETHING well to get an ODP listing. It takes doing some GOOD thing well. (Good, of course, being defined by the ODP mission. If they end up doing professional custom site design for Spamford.Wallace.con, then Mr. Wallace will tell them what "Good" means for him -- and he can reward them based on that definition.)