Automated speed bumps. Cyclists friend or foe?

Trials are taking place in Sweden of the Actibump, an automated speed bump. It uses radar to detect the speed of the approaching vehicle and if it is travelling above the speed limit, it lowers itself into the ground so the speeding vehicle gets a bumpy reminder to slow down.

In theory this is great as conventional speed bumps slow down every car regardless of whether they are doing the speed limit or not and they also cause unnecessary wear on your car.

In the promotional video cyclists do get mentioned with a caption saying “and two-wheeled vehicles can easily avoid Actibump” and the clip shows the cyclist cruising around on the inside of the bump. But what if you are cycling two abreast or you are overtaking another cyclist? What happens if when you are about to ride over it and a speeding car approaches from behind and activates it? What happens if you’re cycling at night and you just don’t see it? What if you are out with club mates on a spin in a large group?

The design itself can be seen to cause quite a bang when a car goes over it when the device is down so we can only imagine what would happen if a bike was to hit it doing 40 km/h.

On the positive side the results from independent evaluation on the implementation of an Actibump and a lowering of the speed limit from 50 km/h to 40 km/h had a very positive impact on motorised traffic.

• 85th-percentile went from 47,2 km/h to 37,0 km/h.
• Average speed decreased by 11 km/h from just over 41 km/h to just under 31 km/h.
• Aside from the Actibump implementation the speed limit was changed from 50 km/h to 40 km/h. Lowering the speed limit (including a change of signage) is a means of speed reduction in and of itself.
• As a general rule of thumb a decrease of the speed limit of 10 km/h gives a decreased speed of 2,5 km/h, in reality.
• Yielding behaviour was already good before installation and still increased by ten percentage points from 72 % to 82 %.

HOW IT WORKS

SEE IT IN ACTION