Hiya

I'd make two comments first. You seem to have used taxiways for ALL the concrete areas including the apron- right? If so, it won't look right. Make your apron from a polygon using concrete.r8 texture or another similar bitmap.

Then make your taxiways of the correct width (in metres) and direction - don't just slap em all over the scenery if you want the right sort of effect (which most of us do!)

Now for texture bleed-thru. Assuming all your altitude/elevations are correct (ie alt of airfield above MSL) then if you get bleed-thru just place the apron/ taxiway textures say 0.05 metres ABOVE the airfield alt (ie at an alt of 0.05m in FSSC).

The last thing is that if you want to taxy over your neew apron and taxiways you'll have to also add smoothing over the relevant areas.

Hope this all helps!

Roger