are joined together to form wooden mats interfitted together to form wooden roadway surface 10 each mat being fastened by screw shank nails 22 a single wooden mat 24 is shown in fig2 repetitively assembled to form the wooden roadway surface 10 of fig1 mat 24 is made up of surface layer 12 comprising substantially parallel longitudinally and closely spaced top wooden planks 13 with intermediate layer 14 supported by underlying layer 18 additionally intermediate layer 14 is seen to include short segment 26 in fig3 the relative orientation of wooden mats 24 to form an assembly of interlocking components can be seen it is to be particularly noted that short segment 26 is mounted at the end of longitudinal bottom planks 20 with such positioning short segment 26 provides a stabilizing effect when mats 24 are placed in relatively soft terrain surface such as sand dirt or muck particularly when wet as longitudinal bottom planks 20 settle in such terrain under the impact of a heavy load traveling on surface layer 12 short segment 26 serves to stabilize the weight carried by mat 24 by preventing longitudinal bottom planks 20 from settling excessively in the surrounding soil a further factor contributing.