“Tires were smoking and engines were screaming” – But did it happen?

Evidence at trials can be complicated and not always accurate.

A trial is taking place involving a dangerous driving charge against a young Cambridge woman, Jasmine Henning, with respect to a collision that reportedly occurred on June 11, 2017 on Water Street in Cambridge. A witness claimed that Henning’s Mazda3 was accelerated from a traffic signal along with a Hyundai Genesis and the witness claimed that “As soon as the light turned green they were gone. Tires were smoking and engines were screaming. They were a couple of pretty fast cars”.

The performance of small engine cars such as the Mazda3 can be altered and that needs to be revealed. However a typical Mazda3 cannot perform the type of accelerations described by the witness. A 300 horsepower Genesis would easily have not problem outracing the Mazda3.

As an example, testing had been performed by Gorski Consulting in June of 2014 involving maximum accelerations of a Mazda3 from initial speeds of 10 and 20 km/h, with the transmission set in 2nd gear. The results of one of the 20 km/h tests are shown in the chart below.

In three tests from 20 km/h the average accelerations, over a time of about 3 to 4 seconds were 0.186, 0.177 and 0.188 g. Similarly, two tests performed from an initial speed of 10 km/h produced accelerations of 0.200 and 0.197 g. These are not massive values. Although the tests were not from a stopped position like the situation reported by the witness, it is highly doubtful that the Mazda3’s performance would be comparable to the Genesis and would not match the witness’s observation of “tires smoking and engines screaming”. That description may be more appropriate for the Genesis.

What actually caused the Mazda3 to travel out of control into opposing traffic needs more study than the small bits of information reported by the news media. Police reported some form of road surface “hump”. That road abnormality may be unrelated to the crash, just as was the opinion of the investigating police.

However, too often, roadway humps, bumps, depressions or subsidences are ignored and untested as possible causes of crashes. This is why Gorski Consulting conducts testing of various road surfaces and road characteristics so that one road can be compared to the next. Without the results from actual, objective testing, the opinions provided by collision reconstructionists and investigators may be inaccurate. The Road Data database is available for public viewing on the Road Data page of the Gorski Consulting website.

When a driver insists that no racing occurred and that some form of unexplainable malfunction occurred this may simply be a way of defending oneself from a serious charge. However when witness information sounds unusual, and police confirm the presence of a road surface abnormality, further study is prudent.