State Highway Patrol members were left shaking their heads when a P-plate driver detected speeding allegedly ignored instruction to pull over in Bonnie Doon yesterday.

Officers say they were patrolling when they detected the Holden utility speeding north along the Maroondah Highway about 6.25pm.

When police activated their red and blue lights, the ute allegedly sped up.

Police say thhe Holden overtook an unmarked police vehicle that was able to detect the speed of the ute, which was allegedly clocked at 186km/h.

A short time later the speeding vehicle slowed down behind a line of traffic and was intercepted by police.

The occupants of the car included a 20-year-old male driver and his 20-year-old female passenger.

He is expected to be charged on summons with speeding and fail to stop for police in the first instance. His vehicle was impounded at a cost of $1350.