Google Maps Adds Live Traffic Support for Additional 130 Cities Across America

Isn't the core value for directions / time costing estimates? Google Now is pretty amazing at estimating my commute based upon the traffic.

Well, the main reason I would choose Google over Caltrans is that it really never occurred to me to go to Caltrans' site. Who expects a government site to be worth a damn?

Snarkiness aside, I've looked at Caltrans now, and Google has more info. There's been ongoing roadwork overnight on the freeway not far from here. Google and Caltrans both show that stretch in red. Additionally, however, Google has icons that when clicked give the hours and exact lanes that are closed. They do the same thing for accident related closures. I don't see anything but the traffic speed on Caltrans' site even with all the checkboxes turned on.

If you tell me that info is on Caltrans site somewhere, I will believe you. I will even believe you if you tell me Google is just pulling their data from an API Caltrans provides. But as the sites themselves go, that info is immediately obvious on Google and not at all obvious on Caltrans.

In the UK at least, the data comes from INRIX (ex Trafficlink), who also supply the traffic news to the vast majority of local and national radio stations. They have a network of cameras and monitoring stations around the country. I don't believe it's crowdsourced from Android users - although I could be wrong.

Having said that, I much prefer going on the BBC Travel News website (which is the same INRIX data) and looking at it in tabular form. I don't find the red/yellow/green lines on roads particularly useful.