We all know that online maps have their faults. One of them is that they tend to be optimistic.
Google and Yahoo maps offer real-time traffic data with color coding on the map of the congested areas. But we all knew that the driving time given on the map was not reliable because it wasn't factoring in the actual traffic conditions.
Well, Google has fixed that. Now, Google Maps offers a time estimate if driving in heavy traffic, such as rush hour.
For instance, if I plan to drive from the CNET offices in downtown San Francisco to Google's headquarters in Mountain View, Calif., (which I do often) the map tells me it's 35.8 miles and should take about 41 minutes, but then underneath that estimate it now says "up to 55 mins in traffic." That also sounds a bit optimistic, but at least it's more realistic than 41 minutes. In reality, I give myself an hour.
Unfortunately, other than red, green or yellow highlights on the maps, they don't (yet) show you exactly what the roadway looks like and where exactly the blockages are. For the traffic obsessed, there is a way to simulate traffic congestion, according to Winding Road blog. The site warns that the microsimulation Java applet is slow and somewhat buggy.