As downloaded a 2004 unzipped traffic file (traffic_'some name'.bgl) cannot be installed directly into 2002.

fs2002 and fs2004 have different ways to  'install' the ai traffic file(s).

2004 can have multiple ai traffic files,  (traffic_'some name'.bgl), therefore the uzipped download file can simply be placed in it's proper location.

2002 only allows 1 ai traffic file named 'traffic.bgl', located in the.....(fs2002)\scenedb\atc\scenery\.. folder. 

For 2002, any new flight plans must be appended to this file using the program 'TrafficTools', available in Utilities downloads section.

I would recommend you stick with fs2002 downloads  and follow the instructions that come with them. You'll need to get 'TrafficTools'.

If you insist on using the fs2004 download,  follow the TrafficTools programs instructions, to decompile, append and recompile the new flightplans into the fs2002 'traffic.bgl' file

Dave