Getting the green light in Austin

January 2016

Like most city streets, there’s lots of traffic lights in our hometown of Mountain View, CA. However, these lights are typically vertically aligned. Last year, when we were deciding on Austin, TX as the next location for our testing program, we noticed that most of the traffic lights were horizontal.

Before our cars drive autonomously in a new location, we first manually drive the area to create a map that allows the car to know what to expect from a street environment — lane lines, how high traffic signals are from the ground, curb heights, bridges. In Austin, one of other tasks was to collect more traffic light data and add it to the database of millions of other examples of traffic lights we’ve seen before. Being able to closely examine each element of driving also allows us to see minute differences (e.g. traffic lights in Austin are dimmer than in Mountain View) and calibrate our sensors accordingly to help us clearly see traffic lights wherever we drive