Tuesday, September 29, 2009

Google Maps and its Traffic overlay

Ever since I started my new job, I've gotten into the habit of turning on the morning news while getting ready for work in the morning. They do reports on rush-hour traffic and this morning, there was one whopper of an accident. A tractor-trailer had slide-lined three cars, completely blocking the flow of traffic in that direction. It was on a road I take everyday to work, but I wasn't sure exactly where on the road it was, so didn't know if it would impact my commute.

Then, I remembered that Google Maps has a live traffic feature that overlays the amount of traffic congestion on the map. I could see where the congestion was and figure out if I needed to find an alternate route. Oddly enough, it reported all roads as being more or less clear, which I knew was not the case. The roadside webcams (another Google Maps overlay) also didn't show any signs of an accident.

It turns out that the data just isn't very "live" after all. Not only was the traffic overlay not reporting the current traffic situation, but the webcam images weren't current either--they were anywhere from 30-60 minutes old. Clicking on the image takes you to the website that operates the webcams, and only going there can you get an up-to-the-minute view of traffic.

So it turned out that my drive wasn't affected. And I learned that, while the traffic overlay on Google Maps is great for seeing general traffic trends, it's not so good for live traffic updates.