How it works
This site / web application is built on top of the traffic layer within Google Maps. The specified layer uses 4 colors to represent traffic congestion: green, orange, red, dark-red. The darker the color is, the more congestion can bee observed in that location.
Every 20 minutes, the web app saves an image for each tracked location, containing the traffic data reported by Google Maps. After a couple of minutes, the images are analyzed, and the percentages of the 4 traffic colors are calculated.
green → P0
orange → P1
red → P2
dark red → P3
Obviously , the sum of all these percentages is 100:
P0 + P1 + P2 + P3 = 100
Based on these percentages, the TCI (Traffic Congestion Index) is calculated:
TCI = (0 * P0) + (1 * P1) + (2 * P2) + (3 * P3)
So the minimum value of TCI is 0, and the maximum value of TCI is 300 (highly improbable to happen). Examples:
|100||0||0||0||0||Awesome traffic (very unlikely to happen in big cities)|
|85.42||7.21||2.51||4.86||26.81||Low traffic congestion|
|41.78||13.08||6.42||38.72||142.08||High traffic congestion|
Frequently Asked Questions
Q: Parks are also green on Google Maps. Did you know that?
A: Of course, but they use different shades of green. They are not taken in consideration when calculating TCI. Same thing applies for traffic markers (ie: road under construction).
Q: What does TCIc mean?
A: It is the TCI, calculated only for the center of the tracked location (the city image is split in 9 equal rectangles, forming a 3x3 grid. The central rectangle is taken into consideration when calculating TCIc).