Bob's Projects

if you are finished with one lod, group all of the single objects by using the "attach" option, then name it reffering to the naming-convention guide.
If you start with doing l3: texture l3 completely and then add more and more details
if you start with doing l1: texture l1 completely and remove more and more details.. logically^^
i guess you started with l1..?

ok, at first display the trianlge count, thats the one that matters

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then select your grouped l1, click on "select and move", hold the "shift key" and drag your object to the left or right. a window pops up, select "clone" and name it reffering to the naming-convention-guide (l2)
now start deleting details and/or merging faces.
in your case that could be the net of the goals or fences (btw. id strongly recommend gbojanics suggestion!), remove the stairs of the terrace and make it flat, delete the metal-structure under the roof, remove small and tiny faces you cannot see from the distance anyway (its hard to tell, just can see a "tiny" picture of your model, no details) (those are just examples!)
always keep an eye @ the triangle count of l2, if you reached the number of triangles (or nearly) do the same procedure for l3

ok, thats not a tutorial, but i hope i could give you an idea of the process anyway

creating l4 is quite easy: just create the main objects like the field, the terrace and floodlights (masts only) as simple as possible (boxes or such). dont split them into smaller faces. keep in mind you wont see any details from that distance anyway.
if you are done use montys l4-projection-baking video tutorial (not sure if its already up here on the new site) for the dif and ill map. done
for future projects i recommend to start with a very simple shaped l4, copy it and then create l3 or l1 (depends on your personal preferences) out of that copy

when removing details always keep the in-game perspective from the distance in mind, and imagine what you could see and what not.
another hint: aitortilla01 's sketchup tutorial also includes a very small lod-tutorial, you might have a look at it.
if you need further information or screenshots just let us know (im sure the pro modders here have some more concrete tipps ) or join the chat^^
well, i hope i could at least help a little bit and give you a roughly idea

edit: yes, sometimes its easier to recreate objects with simple boxes instead of reducing details or merging faces...

 

what you mean by saying that? "for every l1 texture"? you only need one normal map.

looking perfect to me

exactly. one plug, two junctions and one track, use the parameters as sayd in the layout-file instructions

and all in one: great work

 

jep its looking nice
and id say a 2048 is ok for your first mod, but you should change that in future projects.. not because of the hardware, but because of the crappy game-engine but well, maybe in cxxl its no problem, well see
PS: yeah it wont have a big impact if you use one single building with 2048 textures in your city.. but you can imagine if more or everybuilding had such big maps

anyway, great work