Two sorority sisters at Cal Poly San Luis Obispo were allegedly run over by a drunk fraternity brother behind the wheel of a speeding Tesla ... and he fled the bloody crash scene and left them "like run over garbage in the roadway" ... at least according to a new lawsuit.

19-year-old college students Lilianne Burke and Zoey Archibald are suing Ishan Pandhare for allegedly mowing them down with his Tesla on January 8 ... multiple outlets report.

The suit says the 20-year-old frat bro was flying down the road at 60 mph -- even though he was in a 25 mph zone -- when he smashed into the sorority sisters.

The women allege they were walking to a birthday party when Pandhare "came barreling" down the street ... and after he hit them, he didn't stop to help.

The complaint says they were taken to the hospital with major -- but non-life-threatening -- injuries, where they needed surgery and ongoing medical care.

The San Luis Obispo Tribune reports the sorority sisters are suing Pandhare for negligence, as well as some other students and the school's Kappa Sigma fraternity ... who they say had a hand in Pandhare getting drunk and getting behind the wheel.

The women are seeking unspecified damages.

Pandhare's also facing criminal charges for the alleged incident ... including three felony counts of driving under the influence of alcohol, reckless driving causing a specified injury and a hit-and-run causing injury. He pleaded not guilty.