The IndyCar series\' new double-file re-start system will be modified Sunday in a bow to safety in the 100th anniversary edition of the Indianapolis 500. Rather than marking the re-start zone some 900 feet from the start/finish line officials opted to move it back to the entrance to turn four. That will give drivers more room to adjust to traffic on the famed 2 1/2-mile (4km) Indianapolis Motor Speedway oval. \"The owners, along with the IndyCar series, decided to make a compromise and move it into the north chute starting so they can be more single file as they enter turn one,\" said two-time Indy winner Al Unser jnr, an IndyCar driving coach and consultant. \"Indianapolis is very unique as far as single groove. It\'s not a banked track like, say, Texas, where they run two abreast comfortably.\" Double-file re-starts after cautions debuted in IndyCar this season, adopted from NASCAR stock car racing to add more excitement. So far, however, they have only been used on IndyCar\'s street circuits, and Sunday will mark their first use on an oval. The drivers have argued against them all month, saying they\'re impractical with the high-speed, open-wheel cars that can\'t bump each other without disaster as stock cars can. Indy 500 pole-sitter Alex Tagliani has been one of the double-file re-starts\' most outspoken critics, voicing fears of crashes and even debris flying into the stands. \"I don\'t want to be responsible for that,\" the Canadian said. \"If our wheels touch while we\'re racing side-by-side, all of a sudden cars are going to be flipping.\" Officials have also promised two sweepers at each end of the circuit during cautions to clean a wider racing groove in preparation for the re-starts. Switzerland\'s Simona De Silvestro got a taste of the mayhem Indy can produce in practice last week, when a fiery crash left her with burned hands. De Silvestro, one of four women in the field along with US star Danica Patrick, England\'s Pippa Mann and Brazil\'s Ana Beatriz, will start in the eighth row. Her gutsy performance in qualifying her car two days after her frightening crash impressed fans, and De Silvestro received a big ovation when the drivers were introduced to the speedway crowd on Saturday. \"I think it\'s amazing that people are following me like that,\" said De Silvestro, who signed a slew of autographs with her bandaged hands.