Brisbane's Clem 7 tunnel will be fitted with no less than eight fixed speed cameras when it opens early next year.

The cameras - to be placed in pairs at four points along the 6.8 kilometre tunnel - will constitute the highest concentration of fixed speed detection devices in Queensland.

There are currently only nine other fixed speed cameras spread across the state, only six of them operational.

Police Minister Neil Roberts has defended the camera plan as a means of reducing potentially disastrous high speed tunnel crashes, such as that seen in Melbourne's Burnely tunnel which killed three people in a fireball in March 2007.

"Crashes in tunnels have the potential to be particularly hazardous due to the enclosed nature of the environment," Mr Roberts said.