Swiss driver clocked at 312 km/h in Porsche on French A40 motorway

Interception on the A40

French gendarmes intercepted a Swiss motorist travelling at 312 km/h on the A40 motorway during the night between 26 and 27 September 2026. The vehicle was detected in the Arve Valley near Bonneville and Vougy in the Haute-Savoie department, approximately 20 kilometres past the Swiss border near Geneva. The A40 connects Geneva towards Chamonix and carries a posted highway speed limit of 130 km/h. At 312 km/h, the car was exceeding the legal limit by 182 km/h while moving among other vehicles on the motorway. After deducting the standard technical margin, law enforcement authorities registered an official retained speed of 300 km/h, which remains 170 km/h above the permitted limit.

Police action and legal penalties

The interception was executed by the rapid intervention team and the motorcycle brigade of Bonneville. Officers immediately seized the driver's license on the spot and transferred the Porsche 911, identified in media reports as a GT3 model worth several hundred thousand euros, to administrative impoundment. Before leaving the control site, the foreign driver had to deposit a mandatory guarantee payment of €1,500 pending trial. The motorist must soon appear before a French court, where statutory penalties for such speeding offenses include up to three months in prison, a fine of up to €3,750, long-term license suspension, and the permanent judicial confiscation of the vehicle.

Traffic safety and gendarmerie response

The Haute-Savoie gendarmerie shared a photograph of the radar measuring device on social media to show the risks of excessive speed. Law enforcement calculations showed that at 312 km/h, the vehicle covered approximately 87 metres every second, needing barely three seconds to traverse 260 metres without accounting for driver reaction time or braking distance. Joël Contal, deputy commander of the departmental traffic flow control squadron, stated that officers had previously recorded speeds of 230 km/h and 290 km/h, but never an excess of this magnitude.

It is a first in Haute-Savoie. We have already had 230 km/h, 290 km/h, but we have never seen such a speed. In any case, the radar does not make mistakes.

The gendarmerie emphasized that excessive velocity remains a primary contributing factor to fatal collisions on motorways, reminding motorists that public roads cannot be used for racing.

The road is not a racetrack. Let us respect the speed limits. Let us protect lives.

National and international speed records

French news outlets reported the 312 km/h measurement as the highest speeding violation ever recorded by law enforcement on French roads. The event surpassed a previous regional record set four months earlier in May, when a motorist was clocked at 287 km/h on the same A40 motorway in Haute-Savoie. The Swiss national speed record remains higher, dating back to April 2011 when a driver was recorded at 325 km/h in a Bentley Continental on the A1 motorway near Geneva. In Belgium, highway police recorded an even faster violation in 2022 on a motorway in Flanders, where a car was clocked at a corrected speed of 388 km/h, corresponding to an estimated actual speed of 413 km/h.