Australian study finds drivers underestimate speed of approaching trains

Written by Jenifer Nunez, assistant editor
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Drivers can see trains approaching but cannot accurately judge their speed when proceeding through a railroad crossing, a Queensland University of Technology (QUT) and Australasian Centre for Rail Innovation collaborative study has found.

 

Dr. Gregoire Larue, a researcher with QUT’s Centre for Accident Research & Road Safety – Queensland (CARRS-Q) and a research fellow at the Australasian Centre for Rail Innovation, has undertaken field tests to determine if a driver is able to make a reliable judgment to safely proceed through a crossing based on the distance a train is visible and the speed it is travelling.

“Railway crossings are designed to an Australian standard that calculates the sighting distance required to safely navigate a level crossing based on the physics of moving vehicles,” Dr. Larue said.

But he said the formula had been demonstrated to be inaccurate at high speeds for heavy vehicles and a margin of more than 15 seconds extra could be required to safely clear the crossing than what might have been allowed for in the road design.

This issue was tackled in the recent review of the 2007 standard by increasing the sighting distances of crossings to allow additional time when considering heavy vehicle performance. The revised standard was published in March 2016.

“At the upper end of the sighting distances proposed (750 to 1,500 meters [.46-.93 miles]), industry has raised concern around whether a driver would be able to reliably identify a train and assess its rate of approach in order to make an informed decision regarding whether it would be safe to proceed across the level crossing,” he said.

As part of the study, Dr. Larue tested 36 drivers at a site in Victoria to determine the distance they could clearly see and identify a train approaching and their accuracy in calculating the train’s speed.

“What we found was that most drivers could see the train from a very long distance, with 85 percent identifying a train further than 1,450 meters (.9 miles),” he said. “Drivers were also able to identify the train as moving on average at a distance of 1,298 meters (.8 miles) away.

“However, drivers’ estimates of train speeds were very poor and up to 44 percent under the actual train speed.

“At 1,100 meters (.68 miles) away drivers’ speed estimate was on average 44 percent lower than the actual train speed, so despite travelling at 130 kilometers per hour (80 miles per hour) drivers thought the train was travelling at 75 kilometers an hour (46 miles per hour).

Dr. Larue said the study had found that tested drivers were all able to detect the train 750 meters (.46 miles) away.

He said as a result, the standard was revised to ensure that when sighting longer distances, a risk assessment of the location could take account of joint ACRI/CARRS-Q’s research findings to determine if further risk controls need to be applied at the crossing.

“The standard now also includes reference to the human limitations in detecting the movement of the train, particularly beyond 750 meters (.46 miles),” he said.

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