What triggers a suspension from getting Geocode Requests using the google maps API?

I see there is a 50,000 request/day limit for an individual key (roughly 1.73/second)

I just started playing around with the api today and have already been suspended.

I'm trying to get multiple driving directions at once. Is this not allowed?

Is there some way I can view my usage? It would be nice to know that I'm doing something wrong before I get blocked.