You’re tired, take a rest

by James Menzies

KING CITY, Ont. – Imagine being able to roll back the clock and speak to a tired driver before they are involved in an accident. A high-tech, real-time fatigue advisory system being tested by Praxair’s Canadian fleet is allowing the company to do just that, Bob Miskelly told delegates at the Private Motor Truck Council of Canada’s annual convention June 24.

The Advisory System for Tired Drivers (ASTID) was developed by the UK Universities of Liverpool and Loughborough. Loughborough University contributed its expertise on the science of sleep and fatigue while Liverpool provided the technical wizardry. The knowledge-based component of the system provides an electronic template predicting hour-by-hour the likelihood of the driver falling asleep, while the hardware consists of a “steering sensory” system that can detect monotonous driving and the steering inputs that are indicative of a drowsy driver.

A small box inside the cab displays a red light when the driver is showing signs of fatigue, accompanied by an 85-decibel alarm in case the light doesn’t get the driver’s attention. At the same time, an alert is sent to the fleet manager, who can then call the driver and discuss their state of drowsiness and determine whether it’s safe for the driver to carry on.

“I want to know at least an hour or two before you are going to fall asleep that you’re going to fall asleep,” Miskelly explained. The ASTID system provides that opportunity. “Within two minutes (of an alarm) I have a message on my Blackberry and the driver has 15 minutes to pull over. He’s not yet at that stage where he’s going to physically nod off, so it gives us the opportunity to have a conversation with that driver prior to him being upside down in a ditch.”

Generally, a 20-minute “tire check” break is enough for drivers to recharge and fall back within the system’s acceptable level of alertness, however Miskelly said “if his score doesn’t reset (after a break), all the breaks in the world won’t help him and he needs to take eight or 10 hours.”

Praxair’s pioneering of the ASTID system is part of an ambitious global fatigue management program called Fit for Duty. Praxair’s other operations around the world are testing various technologies. In Brazil, for instance, drivers are required to connect the dots on a computer screen within a prescribed time to prove they’re alert enough to begin a driving shift.

However, Miskelly notes pre-trip screening has its flaws, as drivers usually get a rush of adrenaline before taking a test. The Canadian ASTID pilot has great promise, however, and Miskelly said the technology could eventually be deployed in Praxair’s operations around the world.

The ASTID system is non-intrusive, as the unit sits silently when a driver is not exhibiting signs of fatigue. Miskelly said most drivers have welcomed the technology, however he admitted drivers have occasionally objected to the system’s warnings.

“We’ve had arguments with drivers, but we would rather have those arguments than sitting down with them and saying ‘Tell me what you did and why it went over’,” Miskelly said. “A truck that’s laid over on its side or a driver that’s no longer going to be on this earth, that’s a lot harder to deal with.”

The ultimate goal, Miskelly said, is to help drivers modify their behaviour to eliminate fatigue on the job. Findings from the test are also prompting Praxair to take a hard look at its own operations and how they can be modified to reduce driver fatigue.

“It may tell us the driver is okay, but the route we’re travelling on isn’t,” Miskelly said.

For example, the ASTID system has found that drivers who start a driving shift during a low point in their circadian rhythm (times when the body is naturally more fatigued, generally from 2-5 a.m. and 2-6 p.m.) are going to be fatigued by the time they reach their next circadian low point. As a result, long-haul drivers travelling routes such as Edmonton-Winnipeg or from Saint John-Montreal are discouraged from setting out during either of their circadian low points, since they are certain to be fatigued before the end of their driving shift. Beginning a driving shift at 4 a.m., for instance, will virtually guarantee the driver is fatigued by 2 p.m., Miskelly indicated.

“This is how we may end up changing the parameters of how we run our business in terms of trying to accommodate fatigue management for drivers,” Miskelly said.

Praxair has also found that in most cases, a 20-minute rest period is sufficient to reduce a driver’s level of fatigue to within acceptable parameters. Miskelly said a 20-minute break for every three hours of driving time appears to be effective, but it also depends on how that downtime is spent.

“We hope maybe they go for a walk and don’t load up on French fries and gravy,” he said.

The ASTID system isn’t perfect. Miskelly said the lights on the unit can be another in-cab distraction, so the fleet has taped over the green and yellow lights that appear when the driver is still alert enough to be driving. And there have been some false reports caused by things like the vehicle drifting in bad weather, however Miskelly said he’d rather follow up on a false alarm than not know about a driver who’s fatigued and at risk of an accident.

“It’s better to have the phone call to talk about those types of things than other types of things, like where do we send the tow truck?” he reasoned.

Another potential concern for fleets is the cost of the units. Miskelly said they’re about $1,200 each. He also said it’s not enough to install the units in the trucks and forget about them; the ASTID system requires constant oversight by management.

The benefits of the program outweigh any of the negatives, Miskelly said, and drivers are also warming up to it; now they have some validation when they call dispatch and say they’re too tired to continue.

“That warning light in the cab is support for the driver when calling dispatch to advise that he’s fatigued and can’t drive anymore,” Miskelly said. He also indicated there has not yet been an instance where a driver reported being fatigued without it first being detected by the system. Miskelly is so optimistic about the effectiveness of ASTID that he is hoping to move beyond the pilot stage and to further deploy the system across the fleet before he retires in August.

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