i think you are right with where they are.

Daynger:

 

There are speed cameras on entry and exit heading north.

 

There is a camera on entry heading south.

 

In both directions there are three sets of possible locations for cameras, they are located behind speed signage, but the flash unit or radar is located in front of the speed signage. At each point the have one camera box and one radar box per lane, so the cameras could be in any lane or all lanes.

 

From memory heading South they are behind speed sign one, three and the last one, ill have to double check.

 

Heading North the are behind speed signage one three and the second to last one, ill have to double check.

 

I have seen a pic from a car caught in the tunnel, so they can definitely be active.

 

There have been rumors of average speed cameras but nothing confirmed yet that i know of.

 

can confirm the above from experience.... i drive this daily. Averaged speed cameras definitely were a thing, but unsure if that's been turned off following the removal of the south exit camera.

Can't say i'm really all that keen to actually test if averaging still hits going north....