A speeding, drunken motorist who was described as driving like a "bolt of lightning’’ moments before he hit and killed a woman and her daughter has been jailed for 13 years.

Thomas Charles Adamson argued separately with his girlfriend and parents on August 9 last year, but despite his emotional state and having spent the hours beforehand drinking beer, he got into his Holden Commodore and sped along the South Gippsland Highway.

Ma Li Dai (L) and Xinyu Yuan (R).

About 7.20pm he crashed into a car driven by Ma Li Dai, who was leaving a parent-teacher night at Lighthouse Christian College in Cranbourne with her 14-year-old daughter, Xinyu Yuan, and killed them both.

Experts believe Adamson was driving between 155km/h and 165km/h before he hit the brakes – the highway was a 100km/h zone at the time – and had a blood alcohol reading of between 0.120 and 0.165, at least twice the legal limit.