This article was originally posted on the Eco-Scientific web site by Paul Kauler, a self-described independent consultant, truck driver, diesel mechanic, avid student of life sciences and cancer research technician.
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, rolled over in good visibility on a dry stretch of Trans-Canada highway about 13 miles west of Moosomin, Saskatchewan. On several occasions during this trip leading to the accident, the driver had exhibited a lack of basic driving skills as well as a serious lack of judgment. Only a few weeks earlier, that same driver was judged unable to shift and pulled from a 13-speed manual transmission tractor and transferred to a truck equipped with an automatic transmission. Recently hired on by a well-respected Ontario-based transportation firm, this driver had passed his company administered driving test on a truck equipped with an automatic.
From some drivers' perspective, driving with an automatic transmission truck is convenient and easy. But, some driving skills can quickly erode when using automatics on a regular basis, while other skills may never develop; skills such as the ability to free a vehicle trapped in a snow bank or using lower gears when descending a steep hill. Or if they do, they develop very slowly.
One grim reminder of this was the worst bus accident in North American history. On October 13, 1997, a tour bus equipped with an automatic transmission plunged off an embankment following a steep hill descent near St Joseph-de-la-Rive in Quebec. The accident killed 43 out of 48 passengers. Some people believe that using an automatic transmission on long haul trips can increase monotony, leading to a significant decrease in driver alertness, while the need to shift actually increases the driver's level of engagement, increasing alertness by the planning necessary for shifting gears through curves and hills. Unlike with an automatic, a driver using a manual gear box equipped vehicle has advanced warning of approaching fatigue as it is accompanied with deteriorating performance (SafetyNet 2009 Fatigue) as exhibited by more erratic shifting.
A driver's behavior, their fuel economy skills and safety, tend to be related as well. Schneider National carried out interesting analyses of accident rates in relation to drivers' fuel consumption. Schneider's safety and driver education department compared the miles per gallon (MPG) efficiency of its best 100 drivers to its worst 100 drivers. Its 100 "best" drivers had 37% fewer accidents than their "worst" counterparts. When they expanded the study to include the company's "best" 1,000 and "worst" 1,000, the margin dropped, but "best" still maintained a 21% lower accident rate than their "worst" counterparts. These results seem to suggest that a driver's sophistication and skill level have a substantial effect on their road safety performance. Actually, among commercial carriers that rely extensively on automatic transmissions, many have reported an increase in accident rates and CVOR (Commercial Vehicle Operator's Registration) downgrades.
This rather disquieting trend is not helped by the way the FMCSA investigates accidents. Typically, only the category of the vehicle(s) involved; the driver's age, level of experience and physical condition; environmental conditions; and road classification are the variables considered when accident reports are taken and statistics compiled. A proper resolution of the causative factors may be difficult to achieve from the collection of these data points.
Presently, the FMCSA assumes that a driver's skills are proportional to their years of experience. Yet a driver's skill level and judgment are directly related to the type of transmission they use and their time using it. Proper shifting techniques require a level of skill, feel and judgment that only time can provide. And it's this skill, feel and judgment that are necessary to navigate a safe descent of a snow covered hill, whether it's at Golden, B.C., Montreal River Harbour, ON., or an icy stretch of Highway 1 near Moosomin, Saskatchewan.
"... 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."
Mountain Transport Institute
For the safe and efficient operation of their truck, it is essential that the professional driver have absolute control of their vehicle at all times. This is especially crucial during winter weather conditions. Put aside for a minute the frustration felt by drivers that find themselves stuck in a snow bank with only an automatic transmission to work with and spinning tires as their only result; things can turn hairy for them really fast when their automatic transmission unilaterally decides to downshift while their navigating a tricky 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 transmission that "caused" the accident.
The Transport Canada Summary of Heavy Truck Collisions 1994-1998 prepared by the Road Safety and Motor Vehicle Regulation Directorate concluded that "the 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 road conditions for the roll-over I 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 its impacts on road safety.
Automatic transmissions may have a direct impact on highway transportation safety through three mechanisms. Firstly, they enable those who don't have the requisite skill set to drive a truck to obtain their CDL. 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 have an adverse effect on driver alertness. Finally, by performing an unsolicited, pre-programmed maneuver at an inappropriate moment (for example, downshifting when a driver is passing over an icy patch during a sharp curve) they can reduce a driver's control of the vehicle.
In late 2009, Alberta joined a growing list of Canadian provinces placing restrictions on commercial drivers using automatic transmission equipped trucks during road tests (see full article). In 2010, this list included B.C., Alberta, Saskatchewan, Ontario, and Quebec. Also aware of the safety issues connected with the automatic transmission use in road transportation, the European Union is also placing restrictions on the use of automatics by commercial operators. As of this posting, any driver that passed their driving exam using an automatic transmission equipped vehicle will be restricted to driving vehicles with such a transmission. In addition, the European Commission recently installed a forum on the topic of driver training and examinations in relation to commercial vehicles with automatic transmissions. While all this is can be seen as a step in right direction, it might not do much towards solving the problem in the long run if the reasons for these licensing restrictions, as presently implemented in some Canadian provinces and in the European Union, are not adequately communicated to operators and carriers alike.
Left unaware of potential problems, many carriers continue to expand their automatic fleets. The most frequently heard arguments in favor of automatic vehicles are fuel savings and a reduction in maintenance bills; both points that have yet to be validated by comprehensive study. Another argument in favor of automatics is that they allow anyone to drive. The question you have to ask yourself is this, "Do you really want just anyone driving your trucks?"