Rarely has a safety issue so divided people within a sporting series as the current debate about whether Formula One cars should have closed cockpits.

In a style of auto racing in which the driver’s head has always been visible, the subject is the latest area of driver safety, and perhaps the last, that has met with resistance. It has raised questions like few other safety concerns, except perhaps the adoption of seatbelts in the late 1950s.

The debate started in earnest after two drivers died of head injuries over the summer, one in Formula One and the other in the IndyCar series. The French Formula One driver Jules Bianchi, 25, died nine months after his car struck a crane at the Japanese Grand Prix. Justin Wilson, 37, a former Formula One driver from Britain, died a day after he was hit in the head by the nose of another car in an accident at Pocono Raceway in Pennsylvania in August.

With all the safety progress made on cars and track design and with body gear like a device that holds a driver’s head and neck secure from sudden lateral forces in an accident, the open cockpit, which leaves the head exposed, remains the biggest threat to a driver.

In one of the lower series in 2009, Henry Surtees, 18, the son of the former Formula One world champion John Surtees, died when he was struck in the head by a wheel that had come loose from another car. In IndyCar in 2011, Dan Wheldon was killed when he crashed and his head hit a fence pole during a race in Las Vegas.

The last driver to die in Formula One before Bianchi was Ayrton Senna, who was killed in an accident at the San Marino Grand Prix in 1994. In the crash, a piece of Senna’s front wheel suspension pierced his helmet and entered his skull. After his death, Formula One raised the cockpit in cars to protect a driver’s head.

Now, however, there is a more radical suggestion: use a canopy over the driver, as in a fighter jet. But the reactions to this idea have been mixed.

“When we sign up, we know there is still some risk involved and there could potentially be some danger,” said Nico Hulkenberg, a driver for the Force India team in Formula One, “but that is in the DNA of racing in motorsport. We shouldn’t sterilize the whole thing, make everything too clinical and overprotect the whole thing.”

But the Williams driver Felipe Massa, who sustained a serious head injury at the Hungarian Grand Prix in 2009 when a metal bolt from another car pierced his helmet, was not so sure.

“I’m not completely against it,” Massa said of the proposal, “if it’s better for everybody and it doesn’t change the aspect of Formula One.”

Even some of the most adamant proponents of safety in the series are not necessarily convinced, however.

“I don’t know whether it will work or not,” said Jackie Stewart, a three-time world champion who was one of the first instigators of a safety campaign in Formula One starting in the 1960s. “In jet aircraft, the pilots are not even looking; they are looking at displays. We have to see everything on the track. Is it possible to see everything with the bugs, with the oil, with everything that comes up?”

The International Automobile Federation, or FIA, the sport’s governing body, is continuing to study the situation and is seeking another solution.

Charlie Whiting, the FIA technical delegate, said: “We’ve been working on this for a few years and come up with a number of solutions to test, some more successfully than others. We had the fighter-jet cockpit approach, but the downsides to that significantly outweighed the upsides.”

Emerson Fittipaldi, a two-time Formula One champion and the president of the FIA drivers’ commission, pointed out that offshore boat racing had reduced deaths by putting a canopy on the boat’s cockpit. So why not in Formula One?

“It will make it extremely safer for the next generation of drivers,” he said.