This updated NEC4 city track base can be used for the new Northeast Corridor 4.0 route or any metropolitan route which uses concrete ties. The track base gravel texture now uses different and uniform rock and has been lightened to contrast with the ties. Concrete ties have been dirtied, and an oil stripe added. A snow covered track base is also supplied in the download. This track texture modification should look good on most metro routes. Test each for aesthetics and modify those routes which you like. Install is easily accomplished by copying just two files to each route's textures folders. The update is available on the train-sim.com site. Search for the file citytrak.zip.