It doesn’t matter how big the mess, if you can measure it you can analyse it, at least approximately.\u00a0 Nowhere is this more true than for traffic accidents. \u00a0The following illustrates this and how simple it is.\u00a0 It’s also important\u00a0for litigators and insurance consultants to get some idea of the accuracy possible.<\/p>\n
***<\/p>\n
You’ve all seen the\u00a0condition of a car\u00a0after an accident.\u00a0 You could be excused for asking how anyone can get information on the speed of the car(s) at the time of the\u00a0 accident from such a mess – a factor in some insurance\u00a0and\u00a0civil litigation claims. Yet\u00a0experts\u00a0do this.<\/p>\n
It involves measuring the crushed\u00a0part of the car\u00a0at key locations – the damage\u00a0relates to the change\u00a0in speed at the time of the accident.\u00a0 These measurements are then referred to published and proprietary crash data by various sources for the make, model and year of the car.\u00a0 The National Highway Traffic Safety Administration is one source.\u00a0 Finally, putting the relevant data from these sources\u00a0in a\u00a0mathematical formula to get\u00a0information on\u00a0speed at the time of the accident.\u00a0 Laborious but fairly simple.<\/p>\n
Widely used formula have been worked out by others and\u00a0are usually not a concern to the mess measurer at the accident scene.\u00a0 The formulae have a semi-empirical basis – their development is based on both observation and theory, like much in hands-on engineering. \u00a0Hence the approximate nature of the answer on speed.<\/p>\n
***<\/p>\n
The measuring procedure is not too much different from that followed by a land surveyor measuring the height of the ground at\u00a0key locations.\u00a0 The surveyor\u00a0references the measured heights\u00a0to a provincial grid then uses\u00a0the heights\u00a0to\u00a0make a map of the land.\u00a0 In fact, total stations land surveying equipment<\/em>\u00a0is used by some forensic experts to measure – “map”\u00a0a crushed car.\u00a0 The shape of some ground surfaces can also be quite messy, like cars after an accident.<\/p>\n The map or shape of the ground, along with other information, can be used by experts (geo-morphologists) to determine why the\u00a0ground has the shape it does.\u00a0 Similarly, crush measurements\u00a0along with data from\u00a0published sources\u00a0can be used by experts to determine\u00a0why the crushed car has the shape it does.\u00a0 What was the speed to cause this?<\/p>\n ***<\/p>\n I assisted Dr. Stu Smith, C. Tyner and Associates, Halifax\u00a0take these types of measurements on three cars – a Ford,\u00a0a Buick\u00a0and a Nissan, during a meeting of CATAIR in Moncton recently.\u00a0 The cars had been in real traffic accidents.\u00a0\u00a0Dr. Smith\u00a0was\u00a0carrying out a practical exercise – a laboratory test of sorts.<\/p>\n This was\u00a0a follow-up to a lecture on this type of analytical procedure by Mr. Jason Young,\u00a0P.Eng.\u00a0of Advantage Forensics, Inc, Toronto.\u00a0 Mr. Young gave the lecture\u00a0during a CATAIR meeting\u00a0last June in Moncton. (Ref. 1)\u00a0\u00a0Stu and I\u00a0were doing our homework after the lecture along with others at\u00a0the most recent meeting.<\/p>\n We laid out a “box” grid on the floor\u00a0around each of the three cars, simulating the grid used by land surveyors.\u00a0 Measurements were then taken to the crushed steel bumper beam\u00a0in each car referenced to the\u00a0rectangular grid.\u00a0 Stu and the others at the meeting use their respective measurements along with the\u00a0published data and\u00a0a formula to\u00a0get information on speed when the car crashed.<\/p>\n Steel beams have been built in cars in recent years for this very\u00a0purpose – in the event\u00a0the car is in an accident.\u00a0 Even more recently, data recorders\u00a0have been\u00a0installed in new cars to get\u00a0information on\u00a0speed in\u00a0case of an accident.<\/p>\n Findings on speed for the three cars by\u00a0three different\u00a0teams of people using different formulae will be compared with speed information from\u00a0the data recorders in the new cars assessed in our homework.<\/p>\n I\u00a0have a good interest\u00a0in the results of empirical methods\u00a0in\u00a0getting an approximate answer to a problem.\u00a0 Empiricism\u00a0is all around us in the built environment.\u00a0 Theory is in\u00a0the text books.<\/p>\n The data recorder in new cars\u00a0is also certain to have an empirical element – and we expect these results to vary too.\u00a0\u00a0It’s the best we can do with messy cars after a traffic accident. \u00a0But we can do something with simple measurements as I’ve explained, whether with a tape or a data recorder.<\/p>\n (Dr. Smith looked at this item before publication and made helpful suggestions)<\/p>\n References<\/strong><\/p>\n It doesn’t matter how big the mess, if you can measure it you can analyse it, at least approximately.\u00a0 Nowhere is this more true than for traffic accidents. \u00a0The following illustrates this and how simple it is.\u00a0 It’s also important\u00a0for … Continue reading \n