Once all the cars have formed on the grid, after the medical car positions itself behind the pack, a light system above the track indicates the start of the race: five red lights are illuminated at intervals of one second; they are all then extinguished simultaneously after an unspecified time (typically less than 3 seconds) to signal the start of the race. The start procedure may be abandoned if a driver stalls on the grid or on the track in an unsafe position, signalled by raising their arm. If this happens, the procedure restarts: a new formation lap begins with the offending car removed from the grid. The race may also be restarted in the event of a serious accident or dangerous conditions, with the original start voided. The race may be started from behind the Safety Car if race control feels a racing start would be excessively dangerous, such as extremely heavy rainfall. As of the season, there will always be a standing restart. If due to heavy rainfall a start behind the safety car is necessary, then after the track has dried sufficiently, drivers will form up for a standing start. There is no formation lap when races start behind the Safety Car.
onCe aLl thE cARS haVe forMed on The Grid, aftEr The MeDical car positIoNS itsElf Behind tHE pAck, a lIGhT sYsTem abOve the TrAcK IndICatEs the StarT of the RacE: fIVe red LighTs aRe ilLUmiNATED at iNTERvaLs oF one sEcond; tHeY are alL theN ExtiNGuIsheD SIMultAneoUsly AFTer an unSpecified Time (typicalLy LESS tHan 3 sEcondS) TO sIGnal ThE start Of ThE race. THe StaRt PRocEdure May bE abanDoned iF a driVER STaLls on tHe griD or On tHE TracK In An uNsaFe posITiON, sIgnaLLEd bY raISINg ThEIr Arm. IF this HappeNs, the proCeDUre reStarTs: a nEw formatiOn lap BeGiNs wiTh thE OffendiNg car remOved fRom tHE Grid. tHE racE May AlSo bE rESTarted in tHE eVenT Of a sErious acCidenT oR danGErouS cOnditions, witH The origiNal stArT Voided. thE rAce may bE Started fRoM BehinD THe safety caR if RaCe coNTrOL FeelS A Racing stARt wouLd Be excEssiVeLy danGerous, Such As extremelY HeAvy RainfAll. as of thE sEAsoN, theRe WIll alwAys be a standing restArt. if dUE To heaVy RAinfall a staRt beHInd the SAFEty car iS NEcESsaRy, thEN AfTer the Track has dRIEd sUffIcIeNtly, drIveRS will fOrm up For A staNdiNg STaRt. thEre is no fOrmAtIon laP wHeN RAces StARt BehInd THe SafETY Car.