Kwishyiriraho urugi rwinyuma rwinyuma ni ugushyira ibyuma byinshi byimbaraga zikomeye murwego rutambitse cyangwa muburyo butagaragara mumuryango wumuryango wa buri rugi, rukaba rufite uruhare rwumuzamu winyuma winyuma ninyuma, kuburyo imodoka yose "iherekejwe" nabashinzwe umutekano winyuma imbere, inyuma, ibumoso n iburyo, kugirango bagire "urukuta rwumuringa nurukuta rwicyuma", kugirango abagenzi mumodoka bagire ahantu hafite umutekano muke. Birumvikana ko gushiraho ubu bwoko bwumuryango winyuma ya bumper izabura ntagushidikanya ko bizongera ibiciro kubakora ibinyabiziga, ariko kubagenzi mumodoka, umutekano numutekano byiyongera cyane.