▁before ▁the ▁site ▁of ▁the ▁accident , ▁turns ▁on ▁their ▁warning ▁lights , ▁and ▁begins ▁we aving ▁across ▁multiple ▁lan es ▁to ▁signal ▁that ▁other ▁drivers ▁are ▁to ▁slow ▁down ▁and ▁remain ▁behind ▁the ▁officer . ▁The ▁speed ▁to ▁which ▁the ▁officer ▁slow s ▁is ▁based ▁on ▁the ▁amount ▁of ▁time ▁needed ▁to ▁clear ▁the ▁accident ▁ahead . ▁An ▁officer ▁may ▁completely ▁stop ▁traffic ▁to ▁yield ▁larger ▁separation . ▁The ▁second ▁officer ▁then ▁rad ios ▁ahead ▁to ▁the ▁first ▁officer , ▁who ▁is ▁still ▁at ▁the ▁site ▁of ▁the ▁accident , ▁and ▁gives ▁them ▁a ▁description ▁of ▁the ▁last ▁vehicle ▁travel ing ▁ahead ▁at ▁regular ▁spe eds . ▁The ▁first ▁officer ▁will ▁use ▁this ▁information ▁to ▁determine ▁when ▁it ▁is ▁safe ▁to ▁move ▁the ▁accident ▁off ▁the ▁road ▁and ▁onto ▁the ▁shoulder . ▁ ▁Tra ffic ▁breaks ▁may ▁also ▁be ▁conducted ▁to ▁gradually ▁slow ▁traffic ▁in ▁prepar ation ▁for ▁a ▁large ▁accident ▁ahead ▁that ▁has ▁caused ▁traffic ▁to ▁stop ▁ab rupt ly . ▁This ▁greatly ▁reduces ▁the ▁chance ▁of ▁subsequent ▁crashes ▁due ▁to ▁motor ists ▁not ▁bra king ▁in ▁time . ▁Other ▁traffic ▁breaks ▁may ▁give ▁time ▁for ▁construction ▁activities ▁to ▁be ▁completed ▁un inter rupted . ▁Some ▁construction ▁requires ▁equipment ▁that ▁ob struct s ▁the ▁flow ▁of ▁traffic ▁to ▁a ▁point ▁that ▁it ▁becomes ▁a ▁major ▁ha z ard ▁to ▁have ▁traffic ▁trying ▁to ▁travel ▁around ▁them , ▁such ▁as ▁adjust ing ▁the ▁pla cement ▁of ▁a ▁traffic ▁sign , ▁( re ) strip ing ▁l ane ▁markers , ▁or ▁swe eping