Was working in Brussels this week, and on the way back I hunted down the remains of the original tarmac
of the road that hosted the speed trials. These bits are right by the Total services by Jabbeke, heading NW.
From the Wiki entry:
Speed records
In the 1940s and 1950s it was renowned for the number of speed records set on a measured kilometer of highway. Not just absolute speed records, manufacturers wanted each model's maximum speed measured and certified by the Royal Automobile Club of Belgium. For example, the Healey Elliottwith 110.65 mph in 1946, at the time the 'fastest car in the world in series production',[2]the Jaguar XK120achieved an officially timed 126 mph (202.78 km/h); the "Jabbeke Speed Record" Triumph TR2(124.889 mph) car was driven by Ken Richardson; André Piletteset a Belgian record in the 2 litre class in the VeritasRS 206 km/h (128.00 mph); in 1952 the RoverJET 1 turbine driven by Spen Kingset the first speed record for gas turbine cars at 151.965 mph (244.56 km/h) over the flying kilometre; and the exotic Pegaso Z-102clocked 250 km/h (155.34 mph) to make it the 'fastest production car in the world'.