Talk:Fundamental diagram of traffic flow

On our PNG, the labels "stable" and "instable" are backwards on the bottom graph. Look carefully: the third graph contradicts the second. So, is "instable" the region close to congestion, or is it the opposite? How can free flow, with many seconds between cars, be "instable" as the 3rd graph shows? This graph wasn't taken from a textbook, right? The error isn't in some major reference, right? 71.37.36.149 (talk) 00:20, 2 May 2016 (UTC)