Widespread and efficient street lighting is among the elements that set the modern metropolis apart from cities through all of history prior to the mid-19th century. While public street lighting
these days is a huge improvement on the vegetable oil filled lamps used in Ancient Rome, much of the modern infrastructure still relies on outdated technology. The result is low-quality lighting, frequent faults, pollution and the inefficient use of electrical power and lighting services that consume as much as 25% of energy spending in cities. Intelligent street lighting – known as adaptive lighting – includes smart illumination solutions based on efficient, remotely controlled, LED public illumination
. This reacts to usage by dimming the light when its sensors detect no movement, and brightens it when there is activity. It can be set up to suit only road traffic, or can be combined with monitoring of vehicle traffic, the weather and the amount of natural light that is available.