Two British motorsport greats have come out with opposing views on the state of safety provisions in the wake of Dan Wheldon's tragic accident in Las Vegas on Sunday, as the IndyCar Series continues to face criticism for several elements of the fateful season finale.

While sections of the press who would scarcely have given the event a moment's thought prior to the 15-car pile-up which claimed the life of the 33-year old Briton launch into full-on witch-hunts, Nigel Mansell and Sir Jackie Stewart have offered more measured opinions, although both believe that unnecessary risks may have been taken by race organisers at the weekend.

Mansell, who moved to the US-based Champ Car series after winning the F1 world championship in 1992, praised the current level of safety in grand prix racing, and suggested that the Americans could take tips from the top flight. Stewart, who raced in the Indianapolis 500 early in his career, was less enthusiastic about the level of safety in F1, the passionate safety campaigner claiming that improvements could always be made.

"In Indy racing, there is simply nowhere to go," Mansell, who suffered a big hit with the wall in Phoenix at his second CART event before going on to take the series title, told BBC Radio 5Live, "When an accident happens, you are into the wall in a split second. This is why F1 does an exemplary job. The tarmac runs off so the driver has time to decelerate the car."

The Briton was particularly critical of the number of cars allowed to take the start in Las Vegas, with 34 drivers - one more than allowed at the blue riband Indy 500 - lining up for the finale. Wheldon's was the 34th entry, starting in place of the five 'all-stars' the series had hoped to tempt from other disciplines and chasing a $5m bounty if he could win from the back. The rest of the field was made up of seasoned IndyCar competitors, including those chasing the championship, and a number of younger, less experienced racers, some of whom were still in their first season in the series.

"To have 34 cars travelling at at 220mph on a mile-and-a-half long circuit, there are too many cars on the track," Mansell claimed, "The trouble is there are no small accidents when accidents happen. There were a number of rookie drivers and others driving in their first race of the season. The smallest mistakes turn into catastrophic ones and Dan was on the receiving end of it."

Stewart, meanwhile, pointed to modern thinking among race drivers, many of whom believe that there is little danger in making contact with rivals. IndyCar racing, on the ovals particularly, does not have too many instances of deliberate contact, but on-board footage often shows frightening wheel-banging moments of the sort that preceded the pile-up in Vegas.

"We had very few people colliding with each other in my period of racing and thereafter," Stewart, who frequently recalls the death rate in his era of F1, told BBC Radio Scotland, "Now it has become, somehow or other, acceptable and that is a warning.

"Yesterday's accident is sadly a terrible wake-up call and they have to recognise the risk is very real. I think there needs to be more discipline by the governing body. If drivers do consistently collide with each other, there should be heavier penalties. It should be marked down as something that just can't happen."

Stewart pointed to the incident between Michael Schumacher and Vitaly Petrov, in which the Russian vaulted over his rival's car, in the same day's Korean Grand Prix as a evidence that F1 cannot afford to sit back and criticise safety elsewhere. There have been several incidents where F1 cars have taken to the air in the past few years - note Mark Webber's flight over Heikki Kovalainen in Valencia in 2010 - and Stewart wants the sport to be aware that accidents are entirely unpredictable.

"With open-wheel racing cars, it usually means that the car will be thrown into the air because the two wheels turning in opposite directions cause a gear effect and the car gets thrown into the air, as we've seen on several occasions," he confirmed, "There was just that type of accident that occurred in the Grand Prix that took place in Korea and, although nobody was injured, a wheel just needs to touch a driver's helmet and brain damage can be exercised.

"It has now been 17 years, six months and something like 13 days since a driver lost his life in an F1 car, whether it be in testing, qualifying or racing, and I think everybody had grown away from experiencing grief. Every time there is a fatality, there's another wake-up call and one must recognise that motor racing is dangerous and you cannot, because of the long period without fatalities, expect that to go on forever. I think a lot of people will have had an awful shock by the ferocity of the [Las Vegas] accident.

"The law of averages would tell you that, every now and again, there will sadly be a life lost and this is a huge wake-up call for the racing driving fraternity - not just the IndyCar drivers. But we have to recognise that F1 has been one of the examples of how you can make motor racing safer and our risk management is probably unequalled in the world in business or sport.

"[However], when a crash like that happens, you just see how vulnerable and how fragile life is. It has been a very long time since we have had a death, [but] that's something we've got to recognise could happen again and we therefore have to readdress the whole safety business to try to remove as many of the downside risks as possible."