under ideal condition, if the highway sleep imit is 90, u should be driving on the middle.
right lane for overtaking, where left most usually for slower vehicles cuz got merging/exits, & heavy vehicles that has lower legal speed limit or just cant go that fast due to limitation.
if u're doing highway sleep limit, u hab no business being in right most lane.
lantak la the road has speed cam or not, it's none of your busines other drivers willing risk saman for overtaking due to whatever reason.
also, for average speed cam, driver may choose to go fast at the beginning, slowing down on final stretch, or stopping at R&R, & still be under the average speed overall.
You can only use the overtaking lane while still adhering to speed limit though.
The right lane is for overtaking. Not speeding.