4 . ▁It ▁is ▁at ▁the ▁transition ▁to ▁fre ew ay ▁that ▁M - 6 6 ▁starts ▁its ▁conc urrency ▁with ▁I - 1 9 4 . ▁I - 1 9 4 / M - 6 6 ▁is ▁known ▁as ▁the ▁So j our ner ▁Tr uth ▁Dow nt own ▁Park way , ▁but ▁the ▁loc als ▁still ▁use ▁the ▁former ▁semi - o fficial ▁nick name , ▁" The ▁Pen etr ator ". ▁The ▁southern ▁section ▁of ▁the ▁fre ew ay ▁has ▁the ▁highest ▁traffic ▁levels ▁along ▁M - 6 6 ▁as ▁measured ▁by ▁average ▁annual ▁daily ▁traffic ▁( A AD T ) ▁in ▁the ▁survey ▁conducted ▁in ▁ 2 0 0 9 . ▁The ▁Michigan ▁Department ▁of ▁Transport ation ▁( MD OT ) ▁calcul ates ▁the ▁A AD T ▁value ▁as ▁a ▁t ally ▁of ▁the ▁average ▁number ▁of ▁vehicles ▁using ▁a ▁given ▁stretch ▁of ▁road way . ▁I - 1 9 4 / M - 6 6 ▁carried ▁ 2 5 , 2 0 0   ve h icles ▁on ▁the ▁average ▁day ▁during ▁the ▁year ; ▁ 9 8 0   ▁tr uck s ▁were ▁included ▁in ▁that ▁traffic . ▁The ▁fre ew ay ▁continues ▁ ▁north ▁into ▁dow nt own ▁Battle ▁Creek ▁along ▁part ▁of ▁the ▁Kal am az oo ▁River ▁and ▁crossing ▁a ▁branch ▁of ▁the ▁Canadian ▁National ▁Railway ▁and ▁Nor folk ▁Southern ▁Railway ▁before ▁ending ▁at ▁the ▁at - grade ▁intersection ▁with ▁Hamb lin ▁Avenue . ▁I - 1 9 4 ▁ends , ▁and ▁M -