If correctly implemented, generating electricity from a road speed breaker could be actually very straightforward and a permanent source of electricity.
The investment behind it is relatively lower compared to the long term free energy potentials it ensures.
We know that when vehicles step over a speed breaker, it slows down until it has entirely crossed the construction.
Through an appropriate arrangement, the speed breaker hump could be installed with a spring loaded mechanisms which could aid the speed breaking requirement and also absorb the energy from the vehicle movement such that the resultant produces free collectible energy right underneath the speed breaker location.
The conversion could be easily and effectively done through age old traditional method, that is by using a motor generator system.
An example image could be seen below. It shows a piston mechanism where the head surface circumference of the piston coincides with the speed breaker hump curve. This piston head is secured and positioned slightly raised above the speed breaker hump so that the vehicle is able to hit and push it down while passing over it.
The piston is fitted with a spring loaded shaft appropriately installed in a concrete cavity constructed just below the hump.
The piston can be further seen clamped with an alternator wheel such that the perpendicular movement of the piston produces a rotational movement over the connected wheel and the alternator shaft.
Whenever a vehicle climbs and passes over the speed breaker, the piston is pushed down, thrusting a rotational movement over the connected alternator shaft. This happens for as many times a vehicles crosses the speed breaker hump.
The above action is converted into the generation of electricity from the alternator which is appropriately conditioned using a boost converter stage for making the output compatible with the associated battery specification, so that it's charged optimally during the process.
Many such mechanisms may be placed in row across the entire speed breaker length for harnessing the entire section of the area.