Iftiiminta sare ee jaranjarada guud ahaan waxaa lagu rakibay qaybta sare ee gadaasha gaariga, si gaariga loo wado uu fududahay in la ogaado safka gaariga, si looga hortago shilka dambe ee gawaarida. Sababtoo ah gaariga guud wuxuu leeyahay labo nalal oo biriiga ah oo lagu rakibay dhamaadka gaariga, hal bidix iyo mid midig, sidaa darteed nalka jaranjarada sare ayaa sidoo kale nalka jaranjarada ah, nalka jaranjarada. Iftiinka sare ee jaranjarada ayaa loo isticmaalaa in lagu digo gaariga gadaashiisa, si looga fogaado isku dhaca gadaal
Gawaarida aan lahayn nalalka jaranjarada sare, gaar ahaan baabuurta iyo gawaarida mini ee jaranjarada ah markii ay u jeedsan yihiin iftiinka gawaarida dambe, gaar ahaan darawalka gawaarida gawaarida, basaska iyo basaska leh chassis sareeya mararka qaarkood way adagtahay in si cad loo arko. Sidaa darteed, qatarta qarsoon ee shilka gadaal-u-soo-noqoshada waa mid aad u ballaaran. [1]
Natiijooyin tiro badan oo cilmi baaris ah ayaa muujinaya in nalka sare ee jaranjarada uu si wax ku ool ah uga hortagi karo oo yareyn kara dhacdada shilka dambe ee dambe. Sidaa darteed, nalalka jaranjarada sare ayaa si balaadhan loogu isticmaalaa dalal badan oo horumarsan. Tusaale ahaan, gudaha Mareykanka, sida ku xusan xeerarka, dhammaan gawaarida cusub ee la iibiyay waa in lagu qalabeeyaa nalalka jaranjarada sare laga soo bilaabo 1986 xamuulyada khafiifka ah ee la iibiyo waa in ay sidoo kale leeyihiin nalal sareeya.
