The 19-year-old junior for Canberra Brave and one of the team's "brightest young talents" was killed in a crash on the Monaro Highway in the early hours of Monday morning.

Brave chief executive Dan Amodio said the 2021 season would be dedicated to Mr Seary.

Players' jerseys will be embossed with his intials and a pre-season event will be held in his honour.

"To lose Lachy at such a young age and in horrific circumstances is a tragedy beyond words," Amodio said

"As a club, from the front office to the playing group, we will be doing everything we can to commemorate his memory prior to and during the 2021 season."

ACT Policing say investigations into the incident are ongoing and it is not yet known what caused the crash.

The collision between a Toyota Corolla and Honda sedan occurred at 1.20am on Monday.

Paramedics were unable to revive Mr Seary, who was the driver of the Corolla, at the scene.

The other driver was taken to hospital.

Detective Inspector Donna Hofmeier told media on Monday it was disappointing to see ACT's road toll rise so early in the year.

"Ideally we would love to have no road toll at all," she said.

"My message to the ACT public is to think when they are driving; be careful road users, slow down, respect the road and respect other drivers on the road."

It appears the Toyota Corolla vaulted the safety barrier, rolled over and hit a tree.

It appeared the two cars were travelling south on a straight section of roadway.

The incident occurred about 400 metres south of the Tralee Street intersection with the Monaro Highway.

Mr Seary is the fourth person to die on ACT roads in 2021, and the second to die on the Monaro Highway this year, following the death of a motorcyclist at Michelago last Tuesday.