Abstract: In order to prevent the safety accidents in railway dangerous goods transportation,an improved WBS-RBS method was worked out for identifying the risks in it.Firstly,the interval numbers coupled judgment matrix of expert scoring was proposed to improve the WBS-RBS risk matrix.Following this,the midpoints and the half-width of the interval numbers were used for identifying and sorting the whole system WBS-RBS interval numbers,and the probability degree ranking vectors were used for identifying and sorting the unit system interval numbers.Finally,the lithium battery transportation is given as a numerical example to verify the method.The results show that related personnel's dereliction of duty during cargo inspection,personnel's without training during cargo handlings and improper maintenance of rolling stock during the operation of the train generate ultimate risks,that the risk factors in operation of the train are more than those in other operations,that three risks including related personnel's dereliction of duty,improper maintenance of rolling stock and combustion and explosion of lithium batteries have the highest frequency during transportation,and that the interval numbers are helpful in reducing subjectivity and uncertainty in risk identification.

Key words: railway transportation, dangerous goods, work breakdown structure (WBS)-risk breakdown structure (RBS), interval number, lithium battery, risk identification