交通信號燈是(shi)指揮交通運行(xing)的信號(hao)燈(deng)(deng)(deng)(deng)，一般(ban)由紅燈(deng)(deng)(deng)(deng)、綠(lv)燈(deng)(deng)(deng)(deng)、黃燈(deng)(deng)(deng)(deng)組成。紅燈(deng)(deng)(deng)(deng)表示禁止(zhi)通行(xing)，綠(lv)燈(deng)(deng)(deng)(deng)表示準許通行(xing)，黃燈(deng)(deng)(deng)(deng)表示警示。

    交(jiao)通信號(hao)燈分為：機動(dong)車信號(hao)燈、非(fei)機動(dong)車信號(hao)燈、人(ren)行橫道信號(hao)燈、方(fang)向指(zhi)示(shi)指(zhi)示(shi)燈（箭(jian)頭(tou)信號(hao)燈）、車道信號(hao)燈、閃光警告信號(hao)燈、道路與鐵路平面交(jiao)叉道口(kou)信號(hao)燈。

    在十(shi)字路口(kou)(kou)，四(si)面都(dou)(dou)懸掛著紅(hong)、黃(huang)、綠、三色交(jiao)通(tong)(tong)(tong)信號燈(deng)，它是(shi)不出聲的“交(jiao)通(tong)(tong)(tong)警察”。紅(hong)綠燈(deng)是(shi)國際統一的交(jiao)通(tong)(tong)(tong)信號燈(deng)。紅(hong)燈(deng)是(shi)停止(zhi)信號，綠燈(deng)是(shi)通(tong)(tong)(tong)行(xing)(xing)信號。交(jiao)叉路口(kou)(kou)，幾(ji)個方(fang)向來的車(che)都(dou)(dou)匯(hui)集在這(zhe)兒，有的要直行(xing)(xing)，有的要拐彎(wan)，到(dao)底讓誰先走，這(zhe)就是(shi)要聽從(cong)紅(hong)綠燈(deng)指(zhi)揮。紅(hong)燈(deng)亮，禁止(zhi)直行(xing)(xing)或左轉(zhuan)(zhuan)彎(wan)，在不礙行(xing)(xing)人和車(che)輛(liang)(liang)情況(kuang)下，允(yun)許(xu)車(che)輛(liang)(liang)右轉(zhuan)(zhuan)彎(wan)；綠燈(deng)亮，準許(xu)車(che)輛(liang)(liang)直行(xing)(xing)或轉(zhuan)(zhuan)彎(wan)；黃(huang)燈(deng)亮，停在路口(kou)(kou)停止(zhi)線(xian)或人行(xing)(xing)橫道線(xian)以(yi)內，已經繼續通(tong)(tong)(tong)行(xing)(xing)；黃(huang)燈(deng)閃爍時，警告車(che)輛(liang)(liang)注意安全。