Ilambu lamabhuleki aphezulu livamise ukufakwa engxenyeni engenhla ngemuva kwemoto, ukuze imoto eshayela ngemuva kube lula ukubona ingaphambili lebhuleki lemoto, ukuvimbela ingozi engasemuva.Ngenxa yokuthi imoto evamile inamalambu amabhuleki amabili afakwe ekugcineni kwemoto, elinye kwesokunxele nelilodwa kwesokudla, ngakho ukukhanya kwebhuleki eliphezulu kubizwa nangokuthi i-brake light yesithathu, i-high brake light, eyesithathu i-brake light.Ilambu lamabhuleki aphezulu lisetshenziselwa ukuxwayisa imoto ngemuva, ukugwema ukushayisana
Izimoto ezingenawo amalambu amabhuleki aphezulu, ikakhulukazi izimoto nezimoto ezincane ezine-chassis ephansi lapho zibhuleka ngenxa yesimo esiphansi sokukhanya kwebhuleki elingemuva, ngokuvamile ukukhanya okwanele, izimoto ezilandelayo, ikakhulukazi abashayeli bamaloli, amabhasi namabhasi ane-chassis ephezulu ngezinye izikhathi kunzima ukubona ngokucacile.Ngakho-ke, ingozi efihliwe yokushayisana kwengemuva inkulu kakhulu.[1]
Inani elikhulu lemiphumela yocwaningo libonisa ukuthi ukukhanya kwamabhuleki aphezulu kungavimbela ngempumelelo futhi kunciphise isenzeko sokushayisana kwengemuva.Ngakho-ke, amalambu amabhuleki aphezulu asetshenziswa kakhulu emazweni amaningi athuthukile.Ngokwesibonelo, e-United States, ngokwemithethonqubo, zonke izimoto ezisanda kuthengiswa kufanele zifakwe amalambu amabhuleki aphezulu kusukela ngo-1986. Wonke amaloli amancane adayiswa kusukela ngo-1994 nawo kufanele abe namabhuleki aphezulu.