Tests show drivers can’t accurately judge speed of approaching train
Drivers can see trains approaching but cannot accurately judge their speed when proceeding through a passive level crossing, a 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 proceeding through a passive level 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 level 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 1500 metres), 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 per cent identifying a train further than 1450m,” he said.
“Drivers were also able to identify the train as moving on average at a distance of 1298m away.
“However, drivers’ estimates of train speeds were very poor and up to 44 per cent under the actual train speed.
“At 1100m away drivers’ speed estimate was on average 44 per cent lower than the actual train speed, so despite travelling at 130km/h drivers thought the train was travelling at 75km/h.
“At 750m away drivers’ speed estimate was on average 36 per cent lower than the actual train speed, so despite travelling 130km/h drivers thought the train was travelling at 85km/h.
“And at 350m away drivers’ speed estimate was on average 29 per cent lower than the actual train speed, so despite travelling at 130km/h drivers thought the train was travelling at 90km/h.”
Dr Larue said the study had found that tested drivers were all able to detect the train 750 metres away.
He said as a result, the standard was revised to ensure that when sighting distances longer than 750 metres were required, 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 metres,” he said.
Dr Larue’s findings were presented at the Conference on Railway Excellence in Melbourne this month. His research has been published in the Australasian Centre for Rail Innovation final report titled Testing the limitations of Sighting Distances in the AS1742 Part 7 Standard.