optimization of yazd urban transportation and study cause of accidents

transportation as a prerequisite and basics of stable development has a key role and great efficiency in seeding facilities and intellect. it has also a significant role as an effective index in growth and development to the extent that the number of accidents in our country are increasing which carries with them a lot of financial, psychological and social losses, for this reason, it seems to be necessary to put into effect a series of executive solutions to prevent such catastrophes. the aim of this article is to optimize the internal transportation of yazd city with the use of multi-measurement decisive models. methodology the method of this research is descriptive – analytical and its type is basical and developmental. result and discussion the findings of this research shows that 11000 accidents occurs annually in different places of city and 5% of them is with peddlers. the statistical analyses shows that in every kilometer of current roads of first and second degree road collected and disperse of this city 60, 40 and 5 accidents occure annually. it is to be mentioned that the proportion of number of accidents in every 10000 transportation car the distance is approximately about 400 kilometers. a study of network roads of yazd shows that although the roads of these networks are suitably widened and serviceable to the different vehicles, the number of centeral streets such as imam khomeini (between imam sadegh and abozar square) are resolved or nearly resolved and are considered the critical exes. yazd city has 22 crosses of 2, 3 and 4 times. the average time of green distance in all phases is 26 seconds. the overall average time of one cycle of road light for 2, 3 and 4 times is 55 , 77 and 135 seconds respectively. at present there are 200 active buses in 48 bus lines and 140 taxies in 6 taxi lines. out of these taxies, 15 is for railway station, 10 for airport, 30 for external roads, 20 for azad university and 10 are meant for bus station. a survey shows that in 1386 relative to 1385, the number of damaging accidents has been 5.69%, injuring accidents 7.5% and deadly accidents 6.67%. the total accidents had been increased by 6.19%. conclusion the most effective reasons for these accidents have been observance of predecence and paying no attention to the front. in all the accidents occured, personal cars and motor – vehicles have been guilty by 12%. the highest number of accidents occured between 10-12. the roads that accidents have occured are enumerated respectively: ayatollah kashani, jommhori islami, bulvered, shahid dashti bulvered, imam khomeini street, shahid motahari street, shahid paknejad street, daneshju bulvered, shahid sadoughi bulvered, azad shahr bulvered, inghelab street, and in the squares: shahid bahona square, imam hossien square, shohadi mehrab square, abozar square, abolfazal square, homafar square and atlasi square. therefore, there must be a unit of safety management, organizing the information of statistics for accidents, promotion of common information in obtimizing safety, obtimization of network roads, using better transportation means, availing of up- to – date transportion technology for supervising the drivers' faults and growing signs, tablues and safety instrument of roads, obtimizing the rules and regulations, promotion of public transportation system and organizing the roads for vehicles are the only ways to get rid of such accidents.