▁Man j im up ▁was ▁improved ▁in ▁ 1 9 2 6 , ▁as ▁one ▁of ▁the ▁Main ▁Road ▁Board ' s ▁first ▁projects . ▁The ▁worst ▁segments ▁were ▁identified ▁for ▁reconst ruction , ▁as ▁part ▁of ▁an ▁on going ▁process ▁to ▁create ▁a ▁high - quality ▁highway . ▁ ▁Bun bury ▁to ▁Per th ▁ ▁The ▁settlement ▁of ▁Austral ind ▁by ▁the ▁Western ▁Australian ▁Land ▁Company ▁in ▁ 1 8 4 0 – 4 1 ▁prompt ed ▁the ▁first ▁real ▁need ▁for ▁a ▁good ▁quality ▁road ▁to ▁Per th . ▁A ▁coast al ▁Austral ind – M and ur ah ▁route ▁was ▁completed ▁by ▁ 2 ▁November ▁ 1 8 4 2 . ▁Though ▁the ▁road ▁was ▁re built ▁by ▁conv ict s ▁in ▁the ▁ 1 8 5 0 s , ▁its ▁importance ▁was ▁already ▁decl ining . ▁With ▁a ▁new ▁road ▁via ▁Pin jar ra ▁at ▁the ▁fo oth ills ▁of ▁the ▁Dar ling ▁Sc arp ▁completed ▁in ▁ 1 8 7 6 , ▁and ▁the ▁opening ▁of ▁the ▁Per th − B un bury ▁railway ▁in ▁ 1 8 9 3 , ▁few ▁people ▁travel led ▁up ▁the ▁old ▁coast al ▁road . ▁In ▁the ▁late ▁ 1 9 3 0 s ▁there ▁was ▁a ▁proposal ▁to ▁re - est ab lish ▁the ▁road ▁as ▁a ▁tour ist ▁route , ▁which ▁could ▁also ▁reduce ▁traffic ▁on ▁the ▁main ▁road ▁along ▁the ▁fo oth ills , ▁but ▁it ▁was ▁put ▁on ▁hold ▁due ▁to ▁World ▁War ▁II . ▁Im prov