交通信號燈是指揮交通運行的信號燈(deng)，一般由紅(hong)燈(deng)、綠燈(deng)、黃(huang)燈(deng)組成。紅(hong)燈(deng)表(biao)示(shi)(shi)禁止(zhi)通行，綠燈(deng)表(biao)示(shi)(shi)準許通行，黃(huang)燈(deng)表(biao)示(shi)(shi)警示(shi)(shi)。

    交(jiao)通信(xin)(xin)號(hao)燈(deng)分(fen)為(wei)：機動(dong)車信(xin)(xin)號(hao)燈(deng)、非機動(dong)車信(xin)(xin)號(hao)燈(deng)、人行橫道(dao)(dao)信(xin)(xin)號(hao)燈(deng)、方向(xiang)指示(shi)指示(shi)燈(deng)（箭頭信(xin)(xin)號(hao)燈(deng)）、車道(dao)(dao)信(xin)(xin)號(hao)燈(deng)、閃光警(jing)告信(xin)(xin)號(hao)燈(deng)、道(dao)(dao)路(lu)與鐵路(lu)平面(mian)交(jiao)叉道(dao)(dao)口信(xin)(xin)號(hao)燈(deng)。

    在十(shi)字路口(kou)，四面(mian)都懸掛(gua)著紅(hong)(hong)、黃、綠(lv)(lv)、三色交(jiao)通(tong)(tong)(tong)信(xin)(xin)號(hao)燈(deng)，它是不出聲的“交(jiao)通(tong)(tong)(tong)警察”。紅(hong)(hong)綠(lv)(lv)燈(deng)是國際統一的交(jiao)通(tong)(tong)(tong)信(xin)(xin)號(hao)燈(deng)。紅(hong)(hong)燈(deng)是停止(zhi)信(xin)(xin)號(hao)，綠(lv)(lv)燈(deng)是通(tong)(tong)(tong)行(xing)信(xin)(xin)號(hao)。交(jiao)叉路口(kou)，幾個方向來的車(che)(che)都匯(hui)集在這兒，有的要(yao)直(zhi)行(xing)，有的要(yao)拐彎，到底讓誰先走，這就是要(yao)聽(ting)從紅(hong)(hong)綠(lv)(lv)燈(deng)指揮。紅(hong)(hong)燈(deng)亮(liang)(liang)，禁止(zhi)直(zhi)行(xing)或(huo)左轉彎，在不礙行(xing)人(ren)和車(che)(che)輛情況下，允許車(che)(che)輛右轉彎；綠(lv)(lv)燈(deng)亮(liang)(liang)，準許車(che)(che)輛直(zhi)行(xing)或(huo)轉彎；黃燈(deng)亮(liang)(liang)，停在路口(kou)停止(zhi)線或(huo)人(ren)行(xing)橫道線以內，已經(jing)繼續通(tong)(tong)(tong)行(xing)；黃燈(deng)閃爍時，警告車(che)(che)輛注意安全。