From the article:
The EV mode unfortunately has no hold function on it so you can’t decide when to save battery power and when to use it. Why does that matter? Well I knew I was coming up on a traffic snarl, so wanted to save battery power so I could use almost no engine during my traffic jam escapade. But the system kept using battery power because I was cruising along at 105 km/h. When I got to the blockage, the battery was only a quarter full, and the engine ran pretty much the whole time I was doing less than 30. What a waste! Having driven the Volt (granted, a much more significant battery and electric motor) with this save function, I now think it’s a must-have for all hybrids, even non-plug-in hybrids such as this.
I too find this a deficiency. In my case, I know ahead of time if I'm going to be going up or down a long hill, and I'd like to be able to, say, drain the hybrid battery as much as allowed before retarding the speed on the downhill. That way I could get more benefit from the boost prior to the descent and be able to replenish all of that on the descent. The solution is an integrated gps system that keeps track of the terrain, and I understand something like a Bentley hybrid will have this.
In traffic jams, the Escape Hybrid will run the engine continuously only if the a/c is on the normal setting. In that mode, the interior temperature will be maintained at the setting. If you press the "eco" button, it will shut off the engine if it feels the cabin temperature is close enough to the setting. In this setting, you can stop or start the engine by using the "eco" button. This is different for the '10 Escape Hybrid and the peer Prius' because they switched to an electric compressor for the a/c.
With the a/c off and in clogged traffic, the Escape will start the engine only occasionally and run it long enough only to recharge the battery to the 50% level. So in this situation the engine is off most of the time. It does this all by itself, and the Escape's engine stops and starts are not obnoxious. At driving speed, passengers don't even notice it. And that's an '09. It sure seems dumb when you are surrounded by cars not moving and yet their engines are running.