Nalalka bareegga sare leh waxaa guud ahaan lagu rakibaa qaybta sare ee dambe ee gaariga, si gaariga gadaal ka socda uu si fudud u ogaan karo hore ee bareegga gaariga, si looga hortago shilka dambe. Sababtoo ah gaariga guud wuxuu leeyahay laba nal oo bareegga ah oo lagu rakibay dhammaadka gaariga, mid bidix iyo mid midig, sidaa darteed nalka bareegga sare leh waxaa sidoo kale loo yaqaan nalka bareegga saddexaad, nalka bareegga sare leh, nalka bareegga saddexaad. Nalalka bareegga sare leh waxaa loo isticmaalaa in lagu digo gaariga gadaal ka dambeeya, si looga fogaado isku dhaca dambe ee gaariga.
Gawaarida aan lahayn nalalka biriiga sare, gaar ahaan baabuurta iyo baabuurta yaryar oo leh chassis hooseeya marka ay bareega ku jiraan sababtoo ah booska hoose ee nalka biriiga dambe, badanaa ma laha iftiin ku filan, gawaarida soo socda, gaar ahaan darawallada gawaarida xamuulka qaada, basaska iyo basaska leh chassis sare mararka qaarkood way adag tahay in si cad loo arko. Sidaa darteed, khatarta qarsoon ee isku dhaca gadaal waa mid aad u weyn. [1]
Tiro badan oo natiijooyin cilmi baaris ah ayaa muujinaya in nalka biriiga sare uu si wax ku ool ah uga hortagi karo una yarayn karo dhacdooyinka isku dhaca dambe. Sidaa darteed, nalalka biriiga sare ayaa si weyn looga isticmaalaa dalal badan oo horumaray. Tusaale ahaan, Mareykanka, sida ku xusan xeerarka, dhammaan baabuurta cusub ee la iibiyay waa inay ku qalabaysan yihiin nalalka biriiga sare tan iyo 1986. Dhammaan gawaarida yaryar ee la iibiyay tan iyo 1994 waa inay sidoo kale leeyihiin nalalka biriiga sare.
