Amfanin kariyar injin:
1, an tsara allon kariyar injin bisa ga nau'ikan nau'ikan nau'ikan nau'ikan na'urar kariyar injin, ƙirar ta farko don hana injin nannade ƙasa, wanda ya haifar da ƙarancin zafi na injin;
2, na biyu, domin kiyaye lalacewar injin da ke haifar da illar rashin daidaituwar hanya a kan injin a lokacin da ake tuki, ta hanyar tsara zane-zane don tsawaita rayuwar injin, da kuma guje wa rugujewar motar da ta samu sakamakon lalacewar injin da ke haifar da wasu abubuwan waje yayin tafiyar.
3. Bayan yanayin aikin injin yana da ƙarfi, ana rage tazarar kulawa sosai. Za a gudanar da tsarin kula da irin wannan samfurin a kasashen waje na tsawon kilomita 15,000 a shekara, kuma za a takaita shi zuwa kilomita 10,000 a shekara a kasar Sin, har ma za a takaita wasu nau'ikan zuwa kilomita 5,000 na tsawon rabin shekara. An taƙaita lokacin kulawa, kuma farashin kulawa yana ƙaruwa sosai.
