Richard Alvey was driving his Bentley convertible when he crashed on the A458 at the junction with the road to Ludlow at about 10.15pm on July 1.
Other motorists said they estimated that his car had been travelling at around 100mph from Bridgnorth when it hit the road signs on the Ludlow roundabout and flew into the air.
No other vehicle was involved.
At an inquest at the Shirehall in Shrewsbury on Wednesday, senior coroner for Shropshire and Telford and Wrekin, John Ellery, said Mr Alvey had been driving from Bridgnorth Low Town towards the bypass in a Bentley Continental convertible.
He said statements from several other motorists estimated he had been travelling at about 100mph or more as he went up the hill towards the roundabout.
However, the coroner agreed with a member of Mr Alvey's family that the speed could only be their opinion.
Pc Nicholas Stafford, who went to the scene of the crash, said the witnesses said Mr Alvey had made no attempt to slow down or avoid the roundabout.
The police officer said the car hit road signs on the roundabout and was launched onto the grass on the Shrewsbury exit of the junction, flattening trees before coming to rest on the grass.
He said it had still been light when the crash happened and the car had no mechanical defects, while there was no evidence Mr Alvey was intoxicated.
After the crash, West Midlands Ambulance Service said paramedics found the car 15 metres down an embankment, with the 59-year-old still trapped inside. Firefighters had to remove the roof and the driver's door for ambulance crews to assess Mr Alvey.
Mr Ellery said that it was not his place to seek to apportion blame and said his conclusion was that Mr Alvey died in a road traffic accident.