The readme does contain this information, but I will explain it further.
First this is the readme text.
As the ADEX files in this set will replace the same type of file supplied with the ORBx package it is important that they are above the ORBX scenery in your scenery library tree, for all RTMM sceneries you may find it best to create a folder for airfields (RTMM Airports) and inside that you should have a folder called scenery, it is this folder the ADEX filse should go, also any scenery you get that has an ADEX file AND a .cvx file, that should also go in here with the ADEX file.
In the FSX folder is a folder called addon scenery, for the sake of better trouble shooting it is good practice to create sub folder within this folder for different scenery sets.
So, open the addon scenery folder and create a new folder called AI Float Traffic. Now open that folder and create a further folder called scenery, this is the process that should be followed for all sceneris that consist of just bgl and cvx type files, any addon scenery that also has any textures you will also need to create a folder called texture alongside the scenery folder and the textures go in there.
No texture are with this set, so just make a scenery folder. Place the ADEX files into the scenery folder.
Place the traffic.bgl into the FSX\scenery\world\scenery folder
Start FSX
Got to settings then open the scenery library, click the add button and browse to the addon sceney folder then click on the AI float traffic folder to open it, but do not click on the scenery folder, FSX knows all about the scenery folder without need to be told.
click OK, you should not see the AI folder at the top of the tree, this is fine, as long as it is above the ORBx files that's OK.
Click ok to leave the librayr, FSX will rebuild the database to add the new files, fire up the sim and fly off somewhere fun.
