Looks like RIT goes through Hurricane Electric Internet Services (HE.net)
This leads me to believe RIT is hosting their own sites, and probably providing internet access to their students through this same service.
It would therefore make sense that during the weekend, there will be a larger demand on their network due to students not being in class streaming more multimedia, thus causing the packet loss/slowdowns.
But, this is just conjecture. I could be absolutely wrong here.