▁passed ▁by ▁some ▁cars ▁while ▁under ▁ca ution . ▁ ▁There ▁is ▁a ▁notable ▁exception ▁to ▁this ▁rule . ▁If ▁there ▁is ▁an ▁incident ▁during ▁the ▁final ▁lap ▁behind ▁the ▁leaders , ▁and ▁the ▁run ▁to ▁the ▁finish ▁line ▁is ▁clear ▁for ▁the ▁leaders , ▁NAS C AR ▁may ▁delay ▁the ▁ca ution ▁until ▁the ▁check ered ▁flag ▁is ▁shown , ▁allowing ▁the ▁leaders ▁to ▁race ▁for ▁the ▁win . ▁In ▁such ▁cases ▁track ▁safety ▁workers ▁may ▁arrive ▁at ▁the ▁scene ▁of ▁the ▁incident . ▁This ▁exception ▁was ▁used ▁at ▁the ▁ 2 0 0 7 ▁Day ton a ▁ 5 0 0 ▁during ▁a ▁last ▁lap ▁w reck ▁in ▁the ▁tri - oval , ▁the ▁ 2 0 0 9 ▁A aron ' s ▁ 4 9 9 ▁when ▁Carl ▁Edwards ▁went ▁air bor ne ▁into ▁the ▁catch ▁f ence ▁off ▁Ryan ▁New man ' s ▁h ood ▁and ▁came ▁to ▁a ▁rest ▁in ▁the ▁middle ▁of ▁the ▁track ▁as ▁cars ▁sk irt ed ▁to ▁either ▁side ▁to ▁cross ▁the ▁line , ▁the ▁ 2 0 1 3 ▁Day ton a ▁ 5 0 0 ▁where ▁a ▁small ▁w reck ▁occurred ▁in ▁turn ▁ 2 ▁at ▁the ▁back ▁of ▁the ▁pack , ▁and ▁the ▁ 2 0 1 3 ▁Co ke ▁Zero ▁ 4 0 0 ▁where ▁two ▁w re cks ▁unfold ed ▁on ▁the ▁last ▁lap   – ▁one ▁in ▁turn ▁ 2 ▁and ▁another ▁coming ▁to ▁the ▁tri - oval . ▁ ▁Ca ution ▁with ▁two ▁la ps ▁remaining ▁in