A 47-year-old man who had moved to Canberra not long ago is the third motorcyclist "that has lost their life on ACT roads", police said.
Inspector Travis Mills from ACT Policing's road policing unit said the man's family, who lives in far north Queensland, has been informed.
He also said the man died at Canberra Hospital shortly after the crash in Holt on Tuesday evening because of "catastrophic injuries".
The second man involved in the crash, driving a light truck, underwent a routine alcohol and drugs test for impairment at the time of the incident.
Police said he was in a stable condition and had not been arrested or charged.
Inspector Mills said the truck driver was "released from the scene" and continued to assist with inquiries on Wednesday, June 18.
"A brief will be prepared for the corner and the courts in relation to that and I won't provide any further commentary," he told media.
'Concerning' number of road fatalities this year
The inspector said road fatalities in the ACT had doubled since last year and said people needed to think of others around them while driving.
"This is the sixth road fatality. This time last year we only had three," he said, adding the 47-year-old was also the fourth vulnerable road user who had died this year.
"That is a concerning statistic and it is worrying to say the least.
"Police have been clear in their safety messaging for a long time. Please ride and drive to the conditions ... Do not drive distracted and just get to your destination safely."
'Very traumatic'
Some of the first people to arrive at such crashes were members of the public, Inspector Mills said.
"In a lot of cases they're not necessarily equipped to deal with the confronting scenes that they see," he said.
"Police, emergency services, our trauma staff at the hospitals, sadly we see this quite regularly. It doesn't take away from the fact that these scenes are chaotic and very traumatic."
He added such events stayed with everyone involved for a long time.
ACT Policing has urged the community to contact them with any relevant information.
"If [people] were traveling along Southern Cross Drive [on Tuesday] evening at about 10 minutes past five, if they have dashcam footage or if they saw the collision occur, please contact Crime Stoppers ...," Inspector Mills said.
You can contact Crime Stoppers on 1800 333 000, or via the Crime Stoppers ACT website. People are asked to quote P2263637.
