Bumper ifite imirimo yo kurinda umutekano, gushushanya ikinyabiziga no kunoza ikirere kiranga ikinyabiziga. Ku bijyanye n’umutekano, ikinyabiziga gishobora kugira uruhare runini mugihe habaye impanuka yo kugongana byihuse kandi ikarinda umubiri wimbere ninyuma; Irashobora kurinda abanyamaguru mugihe habaye impanuka nabanyamaguru. Kubireba isura, irashushanya kandi yabaye igice cyingenzi cyo gushushanya isura yimodoka; Mugihe kimwe, bumper yimodoka nayo igira ingaruka runaka yindege.
Muri icyo gihe, mu rwego rwo kugabanya imvune z’abagenzi mu gihe habaye impanuka zatewe ku mpande, ubusanzwe urugi rushyirwa ku modoka kugira ngo imbaraga zirwanya impanuka z’umuryango. Ubu buryo ni ingirakamaro kandi bworoshye, hamwe nimpinduka nke kumiterere yumubiri, kandi yarakoreshejwe cyane. Nko mu imurikagurisha mpuzamahanga ry’imodoka ryabereye mu mujyi wa Shenzhen mu 1993, Honda Accord yafunguye igice cy’umuryango kugira ngo yerekane abateranye urugi kugira ngo berekane imikorere myiza y’umutekano.
Kwishyiriraho urugi rwumuryango ni ugushira ibyuma byinshi bikomeye cyane bitambitse cyangwa bitagaragara mumwanya wumuryango wa buri rugi, bigira uruhare rwimbere ninyuma, kuburyo imodoka yose "iherekejwe" na bamperi imbere, inyuma, ibumoso n iburyo, ikora "urukuta rwumuringa nurukuta rwicyuma", kugirango abagenzi mumodoka bafite ahantu hafite umutekano muke. Byumvikane ko, gushiraho ubu bwoko bwa bumper yumuryango nta gushidikanya ko bizongera ibiciro kubakora ibinyabiziga, ariko kubagenzi batwara imodoka, umutekano numutekano byiyongera cyane.
