As many as 55 million streetlights illuminate American roadways today, lighting a path for more than 250 million cars and trucks (Los Angeles Times).
But streetlights predate the earliest cars by thousands of years.
From ancient oil lamps to advanced LEDs, following is a 60-second history of streetlights.
- In ancient Rome, wealthy citizens used vegetable oil lamps to light the front of their homes. Special slaves were responsible for lighting, extinguishing and watching the lamps.
- In 1417, the Mayor of London ordered that all homes must hang lanterns outdoors after nightfall during the winter months. This marked the first organized public street lighting.
- Scottish inventor William Murdoch kicked off a movement toward more efficient street lighting in 1802. His coal-fueled gas light illuminated the outside of the SoHo Foundry for a public presentation. Five years later, London had its first gas-lit street.
- In 1816, Baltimore became the first U.S. city to install gas streetlights. Paris followed closely behind, in 1820. These early gas lights consisted of gas lanterns placed on poles.
- Paris laid claim to the world’s first electric streetlights. Its arc lamps, also known as Yablochkov candles, were installed in 1878. Three years later, 4,000 of these electric lamps were in use, effectively replacing gas lanterns mounted on poles.
- Thomas Edison changed the world when he determined how to create a pure vacuum in his bulbs – something Joseph Swan was unable to achieve. Edison’s carbon-thread incandescent lamp, introduced in 1879, led to the development of light bulbs for streetlights.
- Low-pressure sodium lamps were introduced in Europe in the 1930s. These lamps included a removable outer jacket and a vacuum layer for insulation, maintaining a high temperature to keep the sodium in vapor form.
- American Nick Holonyak, Jr. developed the first practical visible spectrum light-emitting diode (LED) in 1962.
- In 1965, high-pressure sodium (HID) lamps brought superior color and efficiency compared to their low-pressure predecessors. HID lamps are still the most widespread type of streetlight on the planet.
- Modern LEDs last longer, produce better light and use less energy than HID lamps. While LEDs represented a tiny fraction of streetlights in the U.S. a few years ago, the pace of adoption is growing by leaps and bounds.
We’ve come a long way since the days of the ancient Romans. And, thanks to the rapid rise of LEDs, HID streetlights may soon be just as extinct as the oil lamps the Romans used to light long-vanished roads.
Sources: History of Lighting, Journal of Electricity, Power, and Gas, Edison Tech Center, National Museum of American History