This roadbed is reminiscent of the traditional 45-degree slopes found in most commercial model railroad roadbeds.  The scale dimensions are  18" high, 10'-2" across the top and 13' across the bottom.  Actual dimensions are  6.4 mm thick (approx. 1/4"), 6.3 cm across the top (approx. 2-7/16" ), 8.3 cm across the bottom (3-1/4") and 32" long.   Roadbed is sold in 8' bundles.  You receive a bundle of 6 strips, 32" long for each 8' of roadbed ordered.  Roadbed is in halves, so 6 pieces make 96" or 8' of roadbed.  This roadbed is designed so that laying it side to side will yield 3-1/4" track centers.