Washed out lightmap issue. Need advice.

https://drive.google.com/file/d/0BxPjI7V-021yTExBcEVsZDZtSTA/view?usp=sharing

Hi there,
I have a lightmap issue that really annoys me.
Please refer to the attached image above this message. I highlighted the problem with a few arrows.
In front of you see. You see a ladder with a 4 steps. You notice that the steps are becoming slowly brighter and brighter. It looks off . Does anyone know how to resolve this.
FYI : I used 1 wood material for the entire trench. It's all sharing the same material.
FYI : I followed the UDK methodology for custom UV lightmaps.
https://udn.epicgames.com/Three/LightMapUnwrapping.html

 

http://docs.unity3d.com/Manual/LightmappingUV.html

This page seems to be broke.

 

That actually seems correct to me, that there would be more light the further out of the trench you go. I would hardly call that washed out. Nice looking scene!

 

Thank you for taking the time. Speaking of physics, photons etc .you are absolutely right. I agree with you completely.
Makes perfectly sense.

From a visual standpoint. Let me post a screenshot and show you what I mean.
It becomes more obvious in a darker environment, due to contrast.










Could be the uv's of the second lightmap. I am gonna continue experimenting.
I am happy to share results if they are decent.