Having only recently obtained my drivers licence, I noticed that the speedometer on most cars was placed low enough to require the driver's attention to be completely diverted from the road. Given that a driver is meant to check his/her speed at least every 12 seconds, this leads to very frequent distraction. During those 12 seconds it's also possible for the car's speed to drift over the speedlimit, especially in fast traffic.
The solution implemented a rooftop GPS antenna connected to a laptop which was connected to a Vacuum-Flourescent Display mounted on the dash facing the windshield. The laptop processes the GPS signal and using reversed characters, displays the user's speed along with a bar-chart on the display. This image is reflected off the window into the drivers eyes creating a 'floating speedometer' which appears to hang in space just above the bonnet. The bar graph in the output was designed with spaces at key points to allow the driver to more easily determine his/her speed without having to look specifically at the display.
1 Matrix Orbital VFD
1 Generic CompactFlash GPS
1 Generic GPS Antenna
|Computer Hardware:||IBM Thinkpad X20|
|Software:||Python + PySerial|