To recap, this is a 6.5 x 2.5 ft layout in N gauge depicting a fictional TMD based in a hilly rural landscape. The twin loops are to run through tunnels either side and around the back to give the impression of a track going past the TMD rather than looping round it.
At the moment my efforts are concentrated on the left hand end of the layout where the motorway crosses over the railway and the entrance to the depot. There is also a B-road running underneath the motorway to head past and provide access to the TMD before heading up and over the hills on the right hand end.
The road for the motorway is now done, apart from the crash barriers. The road is based on an offcut of MDF. The surface was painted with a mix of greys and thinned 'smoke' paint, then lined with trimline tape for road markings and cats-eyes applied with paint on a cocktail stick. A thin strip of grassmat was used for the central reservation before the whole road was given a thin wash of black to tone down the lane markings a bit.
The bank was made from ceiling coving infilled with polystyrene. A wash of matt earth paint was applied then scatter applied using a spray of diluted PVA. The trees were cut down from 00 gauge wire & flock trees used previously on an 00 gauge diorama. The banks were edged with hardboard painted grey to simulate concrete, and a mirror placed behind the B-road entrance to hide the track behind and give the illusion of the other end of the bridge under the motorway.
The railway tunnel under the motorway was lined with cereal packet card painted grey for a concrete lining. The bridge facing is evergreen I-beam, with a similar facing planned for the road bridge.
Some updated photos:-
Not sure if you can get N gauge Astras though so I might have to apply some modellers licence and use one of the Wiking models.