Driving I 20 eastbound towards Douglas county the driver blantlay sped up to cut me off to get around a semi truck, I proceeded to continue to follow my route to work and flashed my lights at him to let him know inwas there when he cut me off . The driver then decided to throw a red bull can out of his window in an attempt to strike my vehicle. After that . He continued to weave in and out of traffic cutting people off until he exited on chapel hill road in Douglas county