These aren't real-time photos - if you look at San Jose, California, towards the south, southwest of our old home at 543 Bluefield Dr, you can see that the interchange between 85 and 87 is still being built - that was back in 2002-2003.
Real-time data can be overlaid accurately. There are a lot of sources of localized [near-]real-time data available; just need to locate them and figure out how to overlay them - with this technology, that won't be particularly hard.
Lots of cities have real-time traffic cameras; should only take a dedicated programmer a few days to link them all into Google Earth.