Adelaide is testing motion-sensing LED street lights that darken when no one is around.

A strip of 64 of the so-called ‘smart lights’ are in place along Pirie Street and Hindmarsh Square in Adelaide’s CBD.

Adelaide City Council's associate director of IT Peter Auhl said the project sought to balance safety and efficiency.

“One of the key objectives to this project is how we can optimise the amount of lighting that is required to create a safe environment,” Mr Auhl said.

The streets will never be completely dark, with the lights dimming but still offering illumination even when no one is nearby.

But as soon as a pedestrian or vehicle approaches, motion sensors trigger the lights to fire at full strength.

They are equipped with a range of other sensors, such as a light meter that reads ambient light to that the LEDs can be set as low as possible.

The lights are also network enabled, allowing them to communicate data about usages and breakage back to the authorities.

The Adelaide City Council produced the following video to launch the pilot project.