With his wife's shop situated right by a busy streetcar stop, Mike Heavers wanted to build a live bus schedule sign to enable customers to more comfortably browse the shop without fear of missing their bus.
The first step was to make sure that the bus tracking information API was available to use; this will vary by area and service, searching for "[your transit authority name] API" should help you find out if it's available to use. Here in the UK, both Traveline Data and Transport API allow you to access bus timetable APIs for services all over Great Britain for free if you register with them (please check each website's terms of use, as each website will start charging you after you reach certain thresholds, or throttle your access).
The display is powered by a SparkFun ESP8266 dev board, using a strip of NeoPixel LEDs, whilst the display itself is made of laser-cut cardstock and balsa wood. The entire thing WiFi enabled and battery powered, allowing him to move it round the shop to figure out where it works best. This is a great project to make for your own storefronts - or even to put up in your home! If you or a loved one has a problem with chronic lateness, this could make a great visual reminder for when you need to be out the door.
Check out the full project writeup on Hackster.io, where Mike details everything that went right, what went wrong, and what he'd change up next time. It provides a lot of inspiration for making your own version.