Volkswagen have constructed a 30-acre proving ground in Wolfsburg for keeping a constant check on the quality and safety of the Volkswagen. It reproduces all the road surfaces and driving conditions likely to be met with, by drivers all over the world.
A 1.12-mile oval test track runs round the proving ground. The high-speed circuit is made of seamless reinforced concrete and measures 29 ft. 6 in. across. The banked curves permit speeds of 93 m.p.h. without side thrust. The asphalt steering pad is completely level and the radius is 33, 49, 66, 98 and 131 ft. The 33-ft. high hills have four different gradients: asphalt surface for 6 and 12 per cent. and concrete for 20 and 30 per cent.
One half of the 1,960-ft. skid strip’s surface is asphalt, the other is basalt. Special “rain” equipment ensures a dangerously slippery surface. There are strips the same length reproducing an old, often repaired asphalt country road and a very badly paved road. The surface of the pavé track (cobblestones), complete with pot-holes and cracks, was copied from an existing country road. Near the loose sand strips is a concrete corrugated track. It reproduces the conditions found in desert “washboard” tracks and has ridges 1 in. high with 27-in, to 31-in. pitch from crest to crest. The reason for the varying lengths is to enable all possible axle vibrations to be obtained.