Bumper ifite umurimo wo kurinda umutekano, gushushanya no kunoza ikirere kiranga ikinyabiziga.Duhereye ku mutekano, imodoka irashobora kugira uruhare runini mugihe habaye impanuka yo kugongana byihuse, kugirango irinde umubiri wimodoka imbere ninyuma;Mugihe habaye impanuka nabanyamaguru barashobora kugira uruhare runini mukurinda abanyamaguru.Uhereye kubigaragara, birashushanya kandi bihinduka igice cyingenzi cyimiterere yimodoka.Mugihe kimwe, bamperi yimodoka nayo igira ingaruka zindege.
Muri icyo gihe, mu rwego rwo kugabanya ibyangiritse ku bayirimo mu gihe habaye impanuka zatewe n’impanuka, ubusanzwe imodoka ziba zifite ibyuma byo kumuryango kugirango zongere imbaraga zo kurwanya impanuka z’imiryango.Ubu buryo ni ngirakamaro, bworoshye, impinduka nke kumiterere yumubiri, yakoreshejwe cyane.Nko mu 1993 imurikagurisha mpuzamahanga ry’imodoka rya Shenzhen, hafunguwe umuryango wimodoka kugirango berekane bumper abayireba, kugirango berekane imikorere myiza yumutekano.
Kwishyiriraho urugi rwumuryango ni muri buri rugi rwicyapa cyumuryango utambitse cyangwa uhagaritse ibyuma byinshi byuma bikomeye, bigira uruhare mumodoka yimbere yimbere yimodoka, kuburyo imodoka yose ikikije bamperi "kurinda", ikora "icyuma" urukuta ", ku buryo uwatwaye imodoka afite ahantu h'umutekano ntarengwa.Birumvikana ko kwishyiriraho inzugi zumuryango byanze bikunze bizamura ibiciro kubakora imodoka, ariko kubatwaye imodoka, umutekano numutekano biziyongera cyane.
