Engine warning light

[BigBlueSVX]

Every day I drive the same route, and at an exact point in the road the check engine light comes on, from a few seconds to a minute, then goes away. The car drives fine and there doesn't seem to be anything wrong. The engine is still warming up a bit, traveling at about 35 mph. The odd thing is it happens at that exact part of the road, no matter how fast I'm driving. I know it isn't anything to be concerned about, but does anyone have any idea as to what would cause it? thanks in advance.