If American A J Foyt can set land speed records on the flat circular track of the Firestone Test Center (Fort Stockton is it?) with the Oldsmobile Aerotech streamliner, then Europeans should be considered legitimate land speed record breakers at Nardo (which is slightly banked). All you have to think of is a concrete Bonneville speedweek track wrapped into a circle. We do not have any European straights of 12km so this is the best we can use. As you will have read most activity is by car makers in total private with no cameras or visitors.
For the mile and kilo records the runs will have to be two way, according to the FIM rules, with no more than 2 hours between them. Duration speed records can use the whole track in one direction.
The danger is in the overheating of tyres when in a constant turn, which apparently is at speeds above 150 mph in the outer lane.
If you want to see a European circle track look up Millbrook High Speed Test Track, Bedfordshire - a 2 mile true circle in the outer lane and you start turning left from speeds over 100 mph. For safety it is only a counterclockwise operation.
Malcolm UK.