On a warm autumn afternoon, the jurors hearing the inquests of Diana, Princess of Wales, and Dodi Fayed visited the spot in a Paris underpass where the couple’s car crashed on a hot August night ten years ago.

The experience drove the jurors to silence, and they stood briefly with heads bowed in front of pillar No 13, the site of the fatal accident.

Accompanied by Lord Justice Scott Baker, the coroner, and the regiment of lawyers involved in the hearing, the five men and six women walked into the Alma tunnel where Henri Paul crashed on his way to deliver the couple to Mr Fayed’s apartment near the Arc de Triomphe.

Pillar 13 has a large chunk of concrete missing, but so too do several other of the tunnel’s supports, indicating a continuing and dangerous fairground ride of an important Parisian artery. On another nearby pillar a recent graffiti artist has sprayed the inscription, signed and accompanied by a heart: “Diana, on t’aimera toujours.”

Looking overawed by the experience, the jury spent 20 minutes in the tunnel as the coroner led them through the known facts of the case. His main concern was that they observe the pattern of traffic flow. They stood in a semi-circle, and for a full minute they were silenced by where they were and why, briefly bowing their heads. The tunnel was silent, save for the echoing tread of footsteps and the matter-of-fact voice of the High Court judge. Normally, traffic races through the underpass at alarming speed. Police had briefly closed the road, and all others surrounding it, while the participants climbed from their coach for a conducted tour.

It is the first time that an English court has convened on the streets of Paris, and the French authorities were determined that the visit should pass without hitch, throwing more than 400 police, including officers of the French anti-terrorist squad, 200 CRS riot police and plain-clothed members of the Department of Territorial Surveillance — roughly the equivalent of MI5 — at the operation.

But all did not go quite to plan. As the coach carrying the jury behind closed curtains drew up in front of the Ritz Hotel in the Place Vendôme, an elegant square of top-end fashion and jewellery shops, it clipped a metal bollard and blew a tyre with a frightening explosion, throwing its large chrome hubcap several yards across the street.

For nearly an hour the driver and two mechanics toiled to change the wheel on the silver coach. As they struggled with a jack that looked as if it could barely lift a scooter, Victoria Beckham emerged from the hotel accompanied by bodyguards and walked across the square. She may have imagined that the crowd of journalists and cameramen were assembled for her.

A little later than planned, the convoy of three coaches, accompanied by motorcycle outriders, moved off. In the first coach were the jury, the coroner and leading counsel. A second coach carried other lawyers and court officials, bringing the travelling party to about 50. A third, carrying a select group of reporters and cameramen, brought up the rear. They had been told not to photograph members of the jury except from behind, nor to identify them. The first stop was yards away, in the Rue Cambon at the rear of the hotel where the couple left by the service entrance to avoid the crowds and the paparazzi at the front. Closed-circuit television footage seen at the inquest in London last week showed that two photographers, possibly tipped off by Mr Paul, the hotel’s security chief, had worked out the secret plan and were lying in wait across the street.

The convoy turned into the Rue du Rivoli and at Place de la Concorde the jurors disembarked and walked along the northern and western sides of the square. The coroner invited them to study the traffic flow and how it pulsed as the lights changed; it was here that Mr Paul had to choose between the direct route to Mr Fayed’s apartment or to follow the river, possibly hoping to avoid heavy traffic.

The court party rejoined their coaches and turned towards the river, making for the Cours la Reine, the embankment road that becomes the Cours Albert Premier, before heading into the tunnel that carries the road beneath the Pont d’Alma. They drove through the tunnel, turned opposite the Eiffel Tower, went back through the tunnel, turned again and stopped by the entrance.

The court got out again to spend some time on the point of a traffic island watching vehicles flowing on each side of them. The coroner, looking distinguished and unmistakably English, led his party up a slip road on to the bridge above the tunnel, where traffic had been halted, causing jams in all directions and generating curiosity among patrons of the café on the corner. On the opposite side of the bridge is an unofficial shrine to the Princess, where admirers still place wreaths and bouquets, but the party did not get that far. They turned and went back down to the tunnel, now closed to traffic by the police, while the coroner again urged them to observe traffic patterns.

It is only a short underpass. They stood around pillar 13 as the coroner once again went through the events of August 31, 1997, mentioning the mysterious white Fiat Uno that may have been a crucial factor in the crash.

Although it is disputed, Mr Paul was said to have been driving the heavy Mercedes at up to 65mph when he apparently lost control and drove it straight into solid concrete. Today the traffic still takes the underpass at a fair lick, despite a slight bend to the left. The coroner pointed out to the jury that the official speed limit in the tunnel was 50km/h (31mph). “It may be that rather less cars are coming down here in view of what is happening today. But this is quite an important place for you to see,” the coroner said with masterly judicial understatement.

Last night the jury drove the route in the dark, as the Mercedes did a decade ago, and went on to the Pitié-Salpêtrière hospital where the Princess was pronounced dead. The panel saw how she had passed the Louvre, Les Invalides and the cathedral of Notre Dame. They stood by the side of the road nearest to the tunnel and watched the traffic patterns enter the tunnel. There were no plans for them to go in. By that time, they had undoubtedly seen enough.

The inquests continue.

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