After being up and running for three months the Actibumps in Bergen have yielded some results. The 85th percentile speed in the two lanes was 47-50 km/h before installation and is now 38-41 km/h on a road with a speed limit of 40 km/h. As close to perfect results as you can get!
The rate of speeding is now between 5 and 9 % in one direction and less than 2 % in the other lane.
Vestland Fylkeskoomune made a press release at the time of inauguration that tells you a lot about the reactions from drivers of different types of vehicles. Read it HERE. The Google translate version is okay-ish.