Vibration energy harvesting is the solution for powering on-road sensor measurements. Various techniques to harvest the most energy from a certain application are found in literature. An electromagnetic energy harvester was found to be the best option for transport applications. In this work, the potential benefits of a coupled oscillator electromagnetic vibration energy harvester compared to a single degree of freedom vibration energy harvester is explored. This comparison is made based on the steady-state power output when the harvester is excited at its eigenfrequencies. The harvester concepts are compared based on two cases: one where two frequencies are continuously present, and one where two frequencies are alternately present. These cases are derived from on-road container transport measurements. A single degree of freedom and an array of two single degree of freedom harvesters are used as a benchmark. Three configurations of the coupled oscillator harvester concept are presented, which have been optimized with respect to the magnitude of the electromagnetic damping and the ratio between the two masses. It was found that a coupled harvester with two electromagnetic dampers performs as good as an array of two single degree of freedom harvesters. When using the same proof mass for all concepts, a coupled oscillator harvester with only one electromagnetic damper generates less power than one with two dampers. A prototype has been built to validate the simulations. Good correspondence between simulations and experiments was found, both in terms of output power and optimum electromagnetic damping.