qián fāng / jiāo liú dào / fā shēng / shì gù / chē liú / yǐ jīng / huí dǔ / dào / gāo sù gōng lù / zhǔ xiàn前方交流道发生事故,车流已经回堵到高速公路主线。There has been an accident at the interchange ahead, and traffic is already backed up onto the main highway.