Modeling Roads

Foam Roadbed

Contributed by:   Wade Venden

Typical Rural Highway Size

A typical rural highway is of concrete slab construction, with two slabs placed side by side for the length of the road. The slabs are 10 1/2 feet wide x 25 feet long. If curbs are required they 5 foot wide, set back from the main roadway by a curb.

For N-Scale use 2 inches wide for the sub-roadbed, and 1.5 inches for the road itself (2.325" wide when sidewalks are included). For other scales adjust accordingly.

Road Stripes

Roadway stripes, whether rural or urban are [nominally] 4-6 inches wide and the placement varies somewhat depending upon the time era you're modeling. Prior to the early 1970's, centerline stripes were white and no passing zone stripes were yellow. Edge lines were not yet in any widespread use. The pattern was 15' stripe then 25' of space (40' total).

After that time, with the introduction of the newest Federal Manual on Uniform Traffic Control Devices, the striping patterns changed. The centerline as well as the no passing zone stripes all became yellow. The pattern also changed to a 10' stripe with a 30 ' space (still 40' total).  Most lateral spacing is 4" stripe with 4" between the stripes (for dashed and solid stripe applications).

Sign Placement

• Locate 4’ 0" off of edge of roadway.
• For stacked signs (stop & speed limit for example) bottom of lowest sign is 4’0" minimum measured from roadway height.
• For single signs bottom is 6’0" high minimum measured from roadway height

Road Building Materials

The materials needed to build a road vary depending on the type of road under construction; concrete, dirt, or blacktop.  A Brief rundown of what you will need id as follows:

Build up the Roadbed

• Put down basic ground cover.
• First create a flat level surface for where the road will run.   Techniques for this will vary according to how rugged any existing terrain is, and how you built your layout to start with.  If your layout is generally flat, just remove most obstructions under where the road will go.  If the scenery is a little more rugged use plaster to build a surface suitable to drive on.  This can be almost any type of plaster; Sculptamold, Mold-a-Scene, Hydrocal, etc.
• For roads that are basically just dirt tracks, you can stop here.   However in most cases you will want to build up the roadbed above the general ground level.  To do this cut strips of cardboard or foam core board to the appropriate scale width, and lay them where the road will go. Cut the material to match the curves in your new road.  For the larger scales foam core is about the right height, for N scale I use plain cardboard flattened a bit under my shoe.  At any rate, you want this material to top out at a little below the finished roadbed height.
• If you used cardboard for your roadbed either use white glue to attach it to the existing scenery, then cover it with  plaster cloth (or paper towels) to attach it to the benchwork and provide the necessary support.

Blacktop Roads

• Build up any needed contours, such as where the road crosses the tracks, with plaster.  An easy to form plaster such as Sculptamold or Mold-a-Scene is best for this.  Build it up to roughly even with the top of the roadbed.  When dry sand this as needed.
• Paint roadbed with a 50/50 mixture of black and earth colored latex
• Sprinkle with fine dirt/sand to provide texture, covering well. When dry vacuum up the excess texture.
• Apply one more coat of paint over the texture.
• Lightly drybrush the road with Antique White paint.
• After the road has completely dried, take a permanent ink magic marker and draw in cracks and holes.  Use a marker size appropriate for your scale.
• Lightly drybrush the road again, and the road is complete

Dirt Roads

• Use dirt to build up contours where necessary (E.G. rr crossings). Use white glue to hold in place.
• Let dry, then vacuum up excess.
• Paint with diluted earth latex paint, then sprinkle with fine dirt.
• Allow to dry and vacuum up excess
• Seal with another coat of earth latex. Sprinkle with fine dirt again and distress as appropriate. Use small sticks, tires, people for footmarks, etc.
• Wash with black wash mix.
• Drybrush with antique white.