Brian Anthony Brook pleaded guilty to driving more than 35km/h over the speed limit at the Ballarat Magistrates' Court.

Police prosecutor Senior Constable Clint Prebble told the court Brook was caught travelling at 145km/h in a 110km/h zone on the Western Highway near Ballan in February last year.

The court heard Brook told police he was in a hurry to get home to take pain killers for his back.

"It's my birthday. Happy f*ckin' 50th to me," he said as he returned to the car after being pulled over by police. Brook told the court he accepted responsibility for the 'bad' decision to speed.

"I was in a lot of pain, but that doesn't excuse my actions," he said.

"I am begging the court for leniency. We moved to Gordon and this will put pressure on my partner to get me to the train station and will put pressure on my family."

The court heard Brook lost his job when he told his boss what had happened.

Magistrate Ron Saines said Brook would lose his licence for six months, which was the mandatory minimum period.

"You have my understanding and some level of empathy from me on this. The judiciary says a mandatory penalty is unjust, but the parliament continues to do it. One penalty does not fit all. In speeding cases there are minimum periods that are prescribed by the parliament and I have no power to change that... There are no exceptions under the legislation that governs your case."

Brook was fined $600 and ordered to pay $84.90 in court costs.