This Smart Coffee Table Display Real-Time Traffic Conditions

Is there anything worse than getting on the highway for your morning commute, just to find that traffic is worse than usual due to an accident or a light drizzle? If you’re late one more time, your boss is probably going to write you up! One solution is to wake up early and start your commute early to give yourself some buffer time, but that is ridiculous and no sane person would even attempt it. Michael Rechtin made far better use of his time by spending countless hours building this smart coffee table that displays real-time traffic conditions.

Rechtin lives in the beautiful city of Cincinnati, Ohio. Like most American metropolitan areas, it has a spiderweb of interstates and major highways that serve as the main arteries of commuter traffic. Once a minute, Rechtin’s coffee table checks traffic conditions on all of those thoroughfares and shows the results on illuminated map representations. While he sips his coffee, Rechtin can glance at the map to see if he needs to pick up the pace or if he can enjoy a more leisurely morning.

To create the map that serves as the base of the coffee table, Rechtin started with a sheet of thick plywood. He then used a large CNC router to carve the major roads, highways, and interstates into the surface of the wood. He also cut in the Ohio River, which winds through Cincinnati and is a prominent feature of the city.

To make the roads and highways stand out, Rechtin covered the cuts in blank paint. The river received even more special treatment. Rechtin filled that in with a light blue resin (for MSLA 3D printers), then put the entire sheet of plywood out in the sun for a handful of seconds to quickly cure the resin. That makes the river really stand out and it looks great.

The traffic conditions display is made up of strips of WS2812b individually addressable RGB LEDs embedded in 3D-printed translucent plastic. Rechtin printed that plastic on an Elegoo OrangeStorm Giga, which is a huge 3D printer with an 800×800mm bed.

A Raspberry Pi 4 Model B controls those LEDs, changing the colors from green to yellow if traffic is heavy and to red if traffic is bumper-to-bumper. The Raspberry Pi gets that information from the TomTom API, which is free to use when the software stays below the request limit. To avoid exceeding that limit, Rechtin came up with a clever workaround: pulling the city map in chunks and then analyzing the image color at specific points to find the traffic conditions at those coordinates.

After adding a frame and some legs, Rechtin’s smart coffee table was finished. It already looks great when displaying the traffic conditions, but Rechtin also implemented some LED effects modes that are more visually appealing for those times when traffic doesn’t matter.