The Use of Automatic Transmissions - An Issue of Safety?

One sunny afternoon of August 23, 2006 a tractor equipped with an Eaton UltraShift automated transmission, and a tridem trailer loaded with premium Alberta beef destined for Montreal customer was rolled over in good visibility and on a dry stretch of Trans-Canada highway about 13 miles west of Moosomin, Saskatchewan. On several occasions during this trip prior to the accident, the driver exhibited a serious lack of judgement and the lack of basic driving skills. A few weeks earlier, the same driver was pulled from a tractor with 13 speed manual transmission to be transferred on an automatic for not being able to shift. While being hired by a renowned Ontario based transportation firm shortly before that, this driver had passed a company driving test on an automatic.

From some drivers' perspective, driving with an automatic transmission truck is convenient and easy, but... some driving skills erode quickly on automatics. Other skills, such as the ability to free a vehicle trapped in a snow bank for example, or the sense of using lower gears while descending a steep hill never develop. If they do, automatic drivers develop them very slowly. Perhaps, one grim reminder of this was the worst bus accident in North American history, when an automatic tour bus plunged off an embankment and killed 43 out of 48 passengers on October 13, 1997 following a steep hill descent near St Joseph-de-la-Rive in Quebec. Driving an automatic on long haul trips leads to increased monotony accompanied with significant decrease in alertness. In addition, driving an automatic may mask symptoms of approaching fatigue in some drivers. Then the driver may suddenly become overcome by fatigue just as he/she is past a suitable area to park and have some rest. On the other hand, having to shift increases driver's alertness by necessary planning for shifting gears through curves and hills. Unlike on an automatic, on a manual gear box equipped vehicle the driver has advanced warning of an approaching fatigue as it is accompanied with deteriorating performance (SafetyNet 2009 Fatigue) exhibited by more erratic shifting.

Driver's behaviour, his/her fuel economy skills and safety tend to be related as well. Schneider National carried out interesting analyses of accident rates in relation to driver's fuel consumption. Schneider's safety and driver's education department compared its best 100 drivers with its worst 100 drivers, for miles per gallon (MPG) efficiency. Its 100 best drivers for MPG had 37% fewer accidents than the company's worst 100 MPG drivers. When they examined their 1000 best drivers for MPG versus 1000 worst drivers, the best drivers had a 21% lower accident rate. The Schnider's analyses seem to suggest that driver's sophistication and level of skills do have a substantial effect on road safety.

Among commercial carriers, many notorious users of automatics involved in line haul operations experience an increase of accident rates and their CVOR (Commercial Vehicle Operator's Registration) downgrades. This rather disquieting trend in road transportation industry is not helped by the way accidents are being investigated either. Typically, only the category of vehicle, the driver's age, driver's experience, the environmental conditions, road classification and the physical condition of the driver are among the few variables considered in accident statistics. From the collection of these data the proper resolution of the causative factors may be difficult. Presently it is assumed that the driving skills are proportional to the experience of the driver. Yet, the level of driving skills and driver's judgement are directly related to the type of transmission used since to learn a proper shifting technique on a standard transmission equipped vehicle requires certain level of skills and judgement not required to drive an automatic. These skills are acquired by feel and judgement; the same feel and judgement which is necessary for safe descent of a snow covered hill at Golden, B.C., Montreal River Harbour, ON., or making the curve on an icy stretch of Highway 1 in Saskatchewan with 80000 lb units. 

" .... a lot of these people don't have a grasp on the weight they're dealing with because the truck is becoming so easy to drive."
Andy Roberts 
(Mountain Transport Institute, Castlegar, B.C.)

For a professional driver, it is essential to have an absolute control of his vehicle for safe and efficient operation. This is especially crucial during winter weather conditions. Besides the frustrating moments and the feeling of hopelessness one might experience with an automatic tractor when stuck in a snow bank, while only being able spinning the wheels at no avail, things might turn quite hairy when an automatic transmission decides to downshift on its own while one finds himself in a curve on black ice. If the driver lost control of his truck as a result, and ditched his trailer it would be him who would be blamed, and his proficiency and professionalism questioned. Not the automatic truck.

The Transport Canada Summary of Heavy Truck Collisions 1994-1998 prepared by the Road Safety and Motor Vehicle Regulation Directorate concluded that majority of fatal collisions involving heavy trucks occur during daylight hours, in clear weather conditions and on straight and dry road surface much like the roll-over mentioned earlier. Simulator studies such as the one performed by Thiffault and Bergeron and published in Accident Analysis and Prevention in 2003 clearly demonstrate the detrimental effects of monotony on driver fatigue. There is nothing more monotonous than driving an automatic truck on a long distance trip. Yet, the use of automatic transmissions has been spreading for decades without anyone even questioning the impacts on road safety.

Automatic transmissions may impact safety in highway transportation directly through three mechanisms. Firstly, they enable those who should not be driving at all, to drive trucks. Secondly, as pointed out by studies such as the one of Thiffault and Bergeron (2003) and published in Acc. Anal. Prev. 35:381-391, they may affect safety through the reduction of driver's alertness. Finally, they might reduce overall driver's control of the vehicle by performing an unsolicited, pre-programmed manoeuvre at absolutely inappropriate moment (for example, downshifting at the exact moment a driver finds himself/herself passing over an icy patch in a sharp curve).

In late 2009, Alberta joined a growing list of Canadian provinces which placed restrictions on commercial drivers who use automatic transmission equipped trucks on road tests (see full article). In 2010, this list included B.C., Alberta, Saskatchewan, Ontario, and Quebec. Aware of the safety issues connected with the automatic transmission use in road transportation, European Union too, is restricting its commercial operators using automatics. Today, any driver who has performed the driving exam using a commercial vehicle with automatic transmission will receive a driver's licence with a restriction to vehicles with such a transmission. In addition, the European Commission has recently installed an expert forum on the topic of driver training and drivers examinations in relation to commercial vehicles with automatic transmissions. While all this is a step in right direction, apart from yielding useful accident statistics, it might not do much for solving the problem in the long run as the reasons for licensing restrictions presently implemented in some Canadian provinces and in Europe may not be adequately communicated to operators and carriers alike. Perhaps unaware of any potential problems they might still continue expanding their automatic fleets. This is because, the frequently heard arguments for acquisition of automatic vehicles are that they save fuel, and reduce maintenance bills. Arguments, which, with the exception of some limited application to city deliveries were not validated. Another argument in favour of automatics is that they allow anyone to drive. The question we now have to pose is: do we really want "just anyone" to drive our trucks?