The goal
This will help to see the state of roads, in live, just need to load your favorite (urban or not) traffic map.
The screen
I have found a nice screen on ebay for ~18β¬, a 3.2β³ TFT LCD Touch Screen, cheap and small is ideal.
Installing raspbian-DVK512-12040725.img
To use the touch screen, we run under a Raspbian distribution, you can download the image file here already configured to work with the XPT2046 LCD Control (most common 3.2 TFT found on ebay) . Extract the image file on a 2Gb mini SD Card, and run the setup config.
β Calibrate the screen
Go to Preferences, Calibration Touchscreen, follow the instructions.
For more detail: Real-Time traffic state with Raspberry Pi in your car