Nowaday,many big cities are faced with the problem of heavy traffic.Traffic accidents happen almost every day.What are the reasons which happen traffic accidents?In my opinion,maybe there are four reasons.First I feel that the main reason which cause traffic accidents is carelessness of drivers.The first reason includes three cases,some of drivers are very younger,maybe someone has just received driving licence,they feel like to drive his car very fast and their driving skills are not very good,they don’t adopt proper motheds when they meet situation happened suddenly.some of drivers are driving after they have just drunk,they feel nothing themselves,but their mind has been sleeped by alcohol,they are bright in their heart,but they can’t control their emprise,so they often make a car accident.others of them intend to arrive their destination.they drive their own car from night to day,they are so tired that they can’t open their own eyes and see the direction.I think that the second reason is carelessness of pedestrians,most of people don’t have traffic senses,they walk on the roads as if they go at their own home,they think that all of cars dare never hit them,but the buskin has happened.The third reason is poor traffic cndition,because there are more and more people and narrow roads, more and more cars,as is you known the amount of car are increasing at the speed of 10000 per month,however,our road has still been so.Final reason is failure to obey traffic laws,People often say that “you rather stop a minute and don’t snatch a second”,this is a lesson of blood.in order to avoid making traffic accidents,we must obey the traffic rules.With the progress of society and the development of human being,the traffic accidents would often happen if these don’t bring someone’s noticing,we must concentrate on ideas when we are walking or riding on the roads,and we must obey all traffic laws and rules.