350kmh allowed on public road

A driver has cracked 350kmh on a new stretch of freeway in Texas, with the permission of local authorities.

The high speed run recorded a top speed of 220.5mph (355kmh) on electronic timing equipment. That's faster than the 325kmh top speed managed by formula one drivers at the recent Korean Grand Prix.

The run was made to "test" the speed cameras on a controversial new section of freeway in Texas where motorists will be able to go above the usual speed limit if they pay a fee.

Safety advocates claim the private operators of the toll road agreed to pay more than US$30 million (NZ$36.6m) to Texas authorities to have the higher posted speed limit on the 65km stretch of road.

The new toll road, which opened earlier this week, has a speed limit of 85mph (137kmh), well above the usual national posted limits in the US.

The test was organised by car tuner and time-trial driver John Hennessey, who told the Jalopnik website that local authorities had been more than willing to help set up the stunt.

The Texas Department of Transportation even sent a highway patrol vehicle equipped with radar to capture Hennessey's speed. The camera managed to get a clear picture of both front and rear licence plates on the car at a speed of 290kmh.

Hennessey set the speed in a heavily modified Cadillac CTS-V that puts out 895kW of power, roughly twice the output of a V8 supercar.

-Fairfax News Australia