Before 911 (or even household telephones), roughly 500 American cities relied on specialized call boxes tied into police and fire stations for everything from officer check-ins to emergency reports. In many places, these have been abandoned or adapted to new uses, but some still serve their centuries-old function in modern metropolises.

Washington, D.C. got its first wrought-iron fire boxes back in the early 1800s. These were spread out on blocks across the city and tied by telegraph to firehouses. Inside, the turning of a key would send an alarm to the appropriate station. At the station, firefighters would match the signal to a map and deploy a response team. Original boxes still on the streets can be identified by their curved “harp” shape.

The city also later installed a series of police phone boxes. In the absence of two-way radio at the time, these were designed not to be used by citizens reporting crimes but by officers checking in. While making the rounds, they were expected to report back periodically from specific boxes to tell the station all was well in the area. Early call boxes of the police variety were generally more rectangular in shape.

With the advent of home phones and 911, many fire and police boxes fell into disuse. In D.C., they were finally disabled in the 1970s. A few years ago, though, citizens petitioned to give them a new purpose, hoping to populate them with art. The city, for its part, cleaned up hundreds of the old boxes and let communities transform them.

But in some cities, including San Francisco and Boston, there are still some functional boxes. These can be particularly handy during disasters that knock out power and cellular networks.

Other call boxes have come and gone over the years as well. In some places, taxi call boxes allow passengers to hail a cab from a taxi stand. Big retailers also developed networks to allow shoppers to summon assistance within a department store. College and university campuses often space out call stations for people to contact campus security.

Many United States highways have emergency roadside call boxes that either allow normal voice communication or provide a simplified set of color-coded options. In some boxes, for instance, motorists can press blue to report an accident or other emergency, green to request a truck for a broken-down vehicle, black for help with an empty gas tank or flat tire (or yellow to cancel one of those other requests).

But in some places, roadside emergency boxes may be on their way out as well. In California, for instance, the system is expensive to maintain and its usage has declined over time, from nearly 100,000 calls in 2001 to around 20,000 in 2010, presumably due to widespread mobile phone ownership. If these roadside call boxes indeed become fewer and farther between, perhaps they, too, can find a new life housing highway-side artworks.