交通信號燈是(shi)指揮交通運行(xing)的信號燈(deng)，一般(ban)由紅燈(deng)、綠燈(deng)、黃燈(deng)組成。紅燈(deng)表(biao)(biao)示(shi)禁止(zhi)通行(xing)，綠燈(deng)表(biao)(biao)示(shi)準許通行(xing)，黃燈(deng)表(biao)(biao)示(shi)警示(shi)。

    交通信(xin)(xin)號(hao)(hao)燈(deng)分為：機動(dong)(dong)車(che)信(xin)(xin)號(hao)(hao)燈(deng)、非機動(dong)(dong)車(che)信(xin)(xin)號(hao)(hao)燈(deng)、人行橫(heng)道(dao)信(xin)(xin)號(hao)(hao)燈(deng)、方向指示(shi)指示(shi)燈(deng)（箭頭信(xin)(xin)號(hao)(hao)燈(deng)）、車(che)道(dao)信(xin)(xin)號(hao)(hao)燈(deng)、閃光(guang)警告信(xin)(xin)號(hao)(hao)燈(deng)、道(dao)路與鐵路平面(mian)交叉道(dao)口信(xin)(xin)號(hao)(hao)燈(deng)。

    在(zai)(zai)(zai)十字路(lu)(lu)口，四面都懸(xuan)掛著(zhu)紅(hong)(hong)、黃(huang)、綠、三(san)色交(jiao)通(tong)(tong)(tong)信號燈(deng)(deng)(deng)(deng)，它是(shi)(shi)不出(chu)聲的“交(jiao)通(tong)(tong)(tong)警察”。紅(hong)(hong)綠燈(deng)(deng)(deng)(deng)是(shi)(shi)國際統(tong)一的交(jiao)通(tong)(tong)(tong)信號燈(deng)(deng)(deng)(deng)。紅(hong)(hong)燈(deng)(deng)(deng)(deng)是(shi)(shi)停止信號，綠燈(deng)(deng)(deng)(deng)是(shi)(shi)通(tong)(tong)(tong)行(xing)(xing)信號。交(jiao)叉路(lu)(lu)口，幾個方向來的車(che)都匯集在(zai)(zai)(zai)這兒，有的要直(zhi)行(xing)(xing)，有的要拐彎(wan)，到底讓誰(shui)先(xian)走，這就是(shi)(shi)要聽從紅(hong)(hong)綠燈(deng)(deng)(deng)(deng)指揮。紅(hong)(hong)燈(deng)(deng)(deng)(deng)亮(liang)，禁止直(zhi)行(xing)(xing)或左轉(zhuan)彎(wan)，在(zai)(zai)(zai)不礙(ai)行(xing)(xing)人和(he)車(che)輛情況下，允許車(che)輛右轉(zhuan)彎(wan)；綠燈(deng)(deng)(deng)(deng)亮(liang)，準(zhun)許車(che)輛直(zhi)行(xing)(xing)或轉(zhuan)彎(wan)；黃(huang)燈(deng)(deng)(deng)(deng)亮(liang)，停在(zai)(zai)(zai)路(lu)(lu)口停止線或人行(xing)(xing)橫(heng)道線以(yi)內(nei)，已(yi)經繼續通(tong)(tong)(tong)行(xing)(xing)；黃(huang)燈(deng)(deng)(deng)(deng)閃爍(shuo)時，警告車(che)輛注意安(an)全。