Our layouts would improve if we too followed this practice. Building the elevated freeway above the yard was an enjoyable process. It took less than an hour to make the original shape and just a few minutes to prepare the silicon mold. Once the mold cured, each resin casting was made in about five minutes. In half the time it took to model the one styrene column, six perfect resin clones were ready to be planted into the plaster scenery base to support the roadway.
Mold making and casting certainly speeds up any modeling process.
The roadway was built in foamcore and sheet styrene and the road surface was modeled in plaster. The roadway rests on the supports in such away as to be removable to facilitate track cleaning. Everyone has their own formula for making road surfaces look real. Whether I am working on plaster, card stock or wood my technique is the same. I make sure the road surface is always crowned.