Automatic Transmissions – An Issue of Safety?

Editor's Choice posted on 2011/01/11 | 12 Comments |

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."
Andy Roberts
Mountain Transport Institute
Castlegar, B.C.

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?"

12 Comments Subscribe

Anonymous posted on 2013/01/13.

I am a new driver and learned on a 10 speed. I am working for a company that has auto transmission trucks. These trucks seem safer to me because it is one less thing you have to do. You ca keep your eyes on the road instead of on the tach.

Anonymous posted on 2013/01/07.

Im a new to the automatic trucks industry. Im used to manual and the thing is im getting a job on an automatic truck. Im afraid if i say i never operated an automatic i would be cast off. What precautions must i take when driving an automatic truck? Please help.

Anonymous posted on 2012/11/09.

Automatic transmissions have a manual option its a button. Us it on down grades and curves and when u get stuck

Anonymous posted on 2012/10/15.

i drive big trucks for a living, (10 speed manual non sync). it is my opinion that i avoided a severe jacknifife 2 winters ago in icy condiions because of my tranny. any more or less torque to the pavement at one particular slippery spot and i think i would have lost it. i feel very safe having full control of my truck.in all conditions. its almost like i have. a much better awareness of exactly what my truck is doing. my personal cars and trucks are all manual too, for the same reasons. But thats just my opinion. perhaps not all truckers who have had incidents wiith manual or automatic trannys are not around to give us their de briefing.. One quality that i think all drivers should have is confidence and awareness behind the wheel. depending on the driver, that may be with a manual or maybe with an automatic, I might add this P.S. that day i am refering to on ice i was very aware of the bad road conditions and was carefuly monitoring what my truck was doing and i could because i was controlling which gear i was in and my shift points. Call it "seat of the pants driving" Maybe not for everyone . but i think its for me. just one mans story and opinion. Thanks

Anonymous posted on 2012/07/12.

Has anybody heard of the transmissions having problems. We have wet kits on are freighliners and I'm wondering if that could cause the problem also has the deaf included?

Anonymous posted on 2012/05/04.

I thank to all of you willing to express your views on this often-neglected topic. However, your discussion contributions posted between April 2011 and January 2012 also require some comments on my part. First, let me address Shawn’s concerns below:

1- Vehicles with manual transmission take some of driver’s concentration for changing gears for various reasons rather than full attention for monitoring the road and change speed as needed.

R - Not really; this becomes an issue only with green drivers and only during their first few weeks of driving. All more experienced drivers shift subconsciously using audible cues from the engine RPM. A common argument for the use of automatics though!

2- Every vehicle with automatic transmission allows the driver to switch to gear 1 and 2 manually.

R - Yes, but I have never seen anyone doing that. Rather redundant feature, which defies the purpose for automation - convenience.

3- If the truck driver who was pulled from manual tractor and got involved in accident was driving an automatic tractor from the beginning, the traces of manual operations of the previous vehicle in his mind would not bother his easier to control automatic tractor. After all, there is no indication about what went wrong with driving conditions when the driver got into accident.

R - Correct; this also is one of the points of my argument. Human brain is an extremely complex organ, which constantly receives and analyses external environmental cues in order to help us making appropriate decisions. Manual shifting contributes to this cognition by allowing us to better sense the behaviour of our truck and its load in various situations and conditions of the road. This cognition is also commonly known as "the feel of the road". Automatic drivers develop this feel much slower if at all. In case of an accident, currently there is no way of pinpointing the driver's or transmission's technical contribution to an accident (see also comment of John Walschmidt posted on 2011/04/29).

4- In the case of the bus accident, it was not 43 out of 48 bus accidents that had the accidents in steep hill. As the article says the one bus accident that happened to be in steep hill killed the accident killed 43 out of 48 passengers. But what was the other condition that affected the mentioned bus accident and did the other buses with automatic transmission got into same kind of accident and is it true that no bus with manual transmission ever got involved in accident?

R - I do not believe that the issue of safety of automatic transmission has ever been considered either during the investigation of this particular accident or any other. Please, read further below.

5- From my life experience I believe that vehicles with automatic transmission give more time to drivers to control their vehicles.

R - Highway safety is not just a question of having more time to control a vehicle. I agree somewhat with your point raised above, concerning the distraction of some drivers caused by shifting especially when driving in heavy city traffic. Some carriers actually did notice an improvement in safety record during city operations when using automatics. However, data is scarce, and often confounded. Such benefit of automatics may quickly be lost when one considers the safety record of experienced drivers even during city operations. However, manual tranie's do offer better control of a vehicle besides the improvement of human cognition mentioned above.

A few years back, in the middle of winter, tired and at the end of my shift I pulled on a private lot in rural Saskatchewan. It was a fair size dirt lot surrounded with grass fields and heavily used by other truckers for over night rest. This time however, the lot was covered with about a foot of unploughed snow. As I backed my LTL loaded tridem on my spot, the rear axles actually rested on the frozen grass off the edge of the lot. I noticed that only in the morning when I tried to get out. With drive axle locked, the wheels would just spin at no avail. Most of us have experienced this helpless feeling sometimes I believe. With my 13-speed manual trany I was able to rock my tractor with the trailer and 20 minutes later I was back on the highway heading for Regina. Had I have an automatic tractor during this trip, the only way to get out would be sending a satellite message to the dispatch, and then waiting for a heavy tow truck to arrive to pull both my units out. Can you imagine the costs and delays involved?

Automatic transmissions are fine for a senior to drive her car to the plaza for grocery shopping, but professional drivers, and especially those in line haul, need absolute control over the torque going on their drive axle (see also comment by Sharon from AK posted on 2012/01/31). The situation here can be compared to that of fast food. In America fast food became very popular just as automatics have. After all, "why should I learn how to cook and eat a healthy full course meal when I can grab a Big Mac and be fine?" (Is this perhaps why in the US the healthcare is such a good business? I wonder). Because something is easy and convenient it does not necessarily imply it is better or more efficient. What's more, there are two issues about the use of automatics still neglected and to be clarified. Their safety is only one of them. When I tried to raise this issue with Transport Canada a couple of years back, I received quite unprofessional, or even juvenile response. Therefore I had to turn to European Commission. In eight weeks the response from EC came. Apparently, the EU is AWARE OF PROBLEMS WITH THE USE OF AUTOMATICS and established a special expert panel to study the issue. Lo and behold, about six moths later, my above reprinted article was referred to during an on line conference involving several European as well as US institutions.

So to close my comment; after years of neglect, perhaps, finally there might be some studies underway which will help to shed some light on this topic.

The author

Anonymous posted on 2012/01/25.

1- Vehicles with manual transmission take some of driver’s concentration for changing gears for various reasons rather than full attention for monitoring the road and change speed as needed.
2- Every vehicle with automatic transmission allows the driver to switch to gear 1 and 2 manually.
3- If the truck driver who was pulled from manual tractor and got involved in accident was driving an automatic tractor from the beginning, the traces of manual operations of the previous vehicle in his mind would not bother his easier to control automatic tractor. After all, there is no indication about what went wrong with driving conditions when the driver got into accident.
4- In the case of the bus accident, it was not 43 out of 48 bus accidents that had the accidents in steep hill. As the article says the one bus accident that happened to be in steep hill killed the accident killed 43 out of 48 passengers. But what was the other condition that affected the mentioned bus accident and did the other buses with automatic transmission got into same kind of accident and is it true that no bus with manual transmission ever got involved in accident?
5- From my life experience I believe that vehicles with automatic transmission give more time to drivers to control their vehicles.

Shawn Kashfi

Anonymous posted on 2012/01/25.

Anonymous posted on 2011/12/17.

The solution to all of these problems is simple: bring in semi-automatic transmissions that are a combination of the best of BOTH WORLDS: Make it that the driver has to push a small gear shift lever either 'up' or 'down' for the transmission to shift when at higher speeds, yet at lower crawling speeds the truck will act as a fully automatic transmission, this will solve all the problems.

Anonymous posted on 2012/01/31.

I believe there are far more things than shifting of traney that take drivers concentration. Leave traney like it is.....we in alaska need this option. Lot of steep grades that automatic transmission wont stand up to......

sharon in tok, alaska

Anonymous posted on 2011/11/06.

Don't accident statistics indicate whether the vehicle had an automatic transmission or a manual transmission? If not, why?

Why should it be necessary to speculate whether an automatic transmission is more dangerous?

If there are not adequate statistics available to determine for certain whether an automatic transmission is more dangerous, then steps should be taken to gather the statistics and determine for certain, with NO speculation, whether automatic transmissions are more dangerous. There is no excuse for not having statistical proof!

John Walschmidt posted on 2011/04/29.

My brother(truck driver 15yrs) driving an automatic flip the rear trailer exiting a highway. The truck down shifted into the curve causing a middle jackknife effect. It was in damp condition with barely spec tires. Do you have any data of this happening with automatics tractors