Dear Editor,
I was saving this to write a comprehensive treatise on road safety, but the recent minibus road deaths have prompted me to shorten it, to deal for now with the deadly duo, speed and minibuses.
I started my insurance career as a Motor Investigator, trained and certified in the investigation of vehicular accidents, their causes and consequences; delving into vehicle collision dynamics and accident scene reconstruction. Today as an insurer, I literally make a living from how accurately my team could predict the frequency and severity of accidents, and their financial cost. I also explored the science of risky behaviour, decision-making and strategic planning. As a Past President of GMR&SC, racer and builder of race cars, I know a bit about what makes vehicles stable, or rather ‘unstable’ – at speed.
Regarding road deaths, statistics show that Guyana has a poor showing. We rank in the top 50 countries with the highest road fatalities per capita in the World, according to the WHO (2018), with nearly 25 deaths per 1000 people. The highest is Liberia, with 36. Not-so-fun fact: the top 50 countries for road deaths almost all feature these overcrowded death traps known as minibuses, for public transportation. They are, overwhelmingly, underdeveloped states.
Many persons have been rightfully calling for a strategic plan to reduce road accidents. Strategy means doing things differently – very differently. Strategic Change differs from Operational Effectiveness [OE]. OE involves doing the same things more efficiently; which differs from doing the ‘same old’ over and over, hoping for a different result – colloquially called madness. Meaningful strategic change almost inevitably involves some pain; the uprooting of old cultures to change for the better. Change Management is a key management skill.
To craft a strategic plan, one must have a vision of where one wants to be and by when. The plan then must be SMART (look up SMART Planning). One must have priorities, e.g. 1) Reduce the number of road deaths, injuries, and severe accidents; 2) Reduce the cost of road accidents; 3) improve traffic flow.
Everyone knows that severe road accidents are mainly contributed to by excessive speeding. But, how do we eliminate excessive speeding; moreover, its contribution to severe accidents? From a Behavioural Science point of view, pleading, lecturing and threatening have been found to be quite ineffective.
First, let me be clear; excessive speed does not mean a person going 5 mph over the speed limit on a clear day, simply because they did not have their eyes glued to their speedometer. Vital police resources are wasted when several policemen hide around the corner with a speed gun to entrap drivers who inadvertently go a few mph faster than the limit. To approach speed control, you must understand speed and the psychological factors involved in this risky behaviour of speeding. On this, one can write volumes, so here are some essentials.
There are two real problems with speed. First, the average person knows that as speed increases, we have less time to think and react, often less time than is needed to avoid an accident. Speed therefore increases the likelihood of an accident because it hampers driver efficiency.
The second, is that speeding means increased momentum and force, leading to more severe accidents – harder hits. Hidden from the layperson, is the not-so-obvious science of vehicle dynamics – how any particular vehicle reacts to driver action. Vehicles are less stable at speed because of the physics of motion, and how this relates to the configuration of the vehicle, in particular the way it grips the road when a driver acts.
Putting these two together, the driver at speed has too little time to make the right decision, and because speed makes the vehicle unstable, the situation becomes deadly on the road.
Three related things we ought to understand about speed are first, that vehicles need a straightaway in which to build speed; second, that speed increases the forces that reduce the grip of the tyres on the road; and thirdly, that weight on the tyre (within the weight tolerance of the tyre) increases its grip. That’s why the big guy is at the back of the tug-o-war team. Race car engineers do lots of things to increase grip, for example by placing wings on the car in the upside-down position as on a plane taking off, to increase ‘downforce’ or aerodynamic ‘weight’ on the tyres. Roundabouts are much safer as intersections. Not only do they eliminate T-junction (‘T-bone’) accidents (the worse type), but the vehicle would spin around at relatively slow speed should anyone attempt to speed around a roundabout. It’s a whole lot of physics, but let’s accept that when a vehicle is moving in a turn, swerve or manoeuvre, it would have less grip. And the faster it does so, the lower the grip.
With these facts in mind, we can now discuss how speeding gives rise to accidents and what we could do to prevent them. We cannot eliminate long straightaways, but we could police them. Instead of hiding round the bend of the most innocuous corner, we must pay close attention to which long straightaways give rise to the most severe accidents. And we have a clear winner – long straightaways that have dangerous bends at the end. One of the most dangerous bends is the slight bend. Why? Because, these turns fool drivers into thinking they can take them at higher speeds; with disastrous results, because, (unlike at the roundabout) when they eventually lose control they end up in a high-speed collision; either by drifting over into the oncoming lane, hitting the median, or swerving to correct this and completely losing control.
The situation is made worse when the long straightaway has those dips and bumps before the turn. Dips and bumps when taken at speed throw the vehicle up on its ‘tiptoes” when its tyres barely touch the roadway. Less downforce (weight) means less grip, and control is lost, the vehicle begins to slide or drift out of the driver’s control. Most drivers do not know how to control a high-speed drift – a race car driver’s greatest skill, requiring nerves of steel even with racecar safety – so they usually swerve or panic brake, further exacerbating the instability of the vehicle.
Solution: Place police barriers or have police checkpoints about two-thirds of the way along long straightaways; especially those followed by slight curves, bumps or dangerous bends. A few examples – Mandela Ave round the Botanical Gardens. Vreed-en-Hoop- the swing by Versailles; Sparendaam’s curve. They are numerous others. Infamously now, as you drive on the straightway past MovieTowne heading to town; not only are you confronted by the treacherously illusive slight turn, but it is preceded by a dip and bump which gets the speeding car unstable. Soon the speeding driver realizes that he is drifting towards the median, so he pulls left, sending to car into a spin heading inwards.
Place your palm on the desk, and raise your thumb and little fingers. The part that is touching the desk is all the contact a car or bus has between it and the road at each wheel, no matter how fast it goes; nothing else. That tire contact patch (‘contact-patch’) is critical to whether the vehicle stays stable, spins, or rolls over; how, when and where the driver loses control.
You could imagine now that tyres are vital to the stability of a vehicle; and that’s why we need the newest, best-maintained tyres on our vehicles; and the correct tyres for the purpose. I have seen way too many accidents causes by bad tyres. Bad tyres and speed, equals disaster. Racecar engineers know that the difference between a win and an ‘also-ran’ is often down to tyre condition. That’s why in a Formula-1 race, it’s all down to tyre strategy.
Solution: have a system that incentivizes new-tyre use.
We all know that minibuses are among the biggest contributors to road carnage. What we have is a system where the income of the bus driver and conductor depends, in their minds at least, on how fast they could go and how many reckless chances they could take. Minibuses are in the vast majority driven by young males from lower-income areas. Studies reveal that they are the highest road risk-takers by age, gender and socio-economic status. This is particularly so in the countries with the highest road fatality ratios.
Remember, stability has a lot to do with what keeps the tyres firmly on the road and gripping. Notably, the suspension components of the vehicle and the wheels themselves are critical. Minibuses are sadly illustrative.
Have you ever noticed that most minibuses, especially the speeding fancy ones, have their wheels sticking out the sides? Have you ever noticed that the wheels often look wider than the tyres? Maybe this is supposed to look racy and exciting, but I assure you no proper racer would do that. Wider wheel tracks do lead to more stability but not like that.
Imagine someone pushing you sideways to your left. If you were to bend your left knee, and tense those leg muscles, you would be able to stabilize yourself. Now imagine getting the push with your whole leg remaining straight and stiff; you would fall over much easier. Well the suspension in the vehicle performs the vehicular equivalent of flexing and bending your knees to stabilize it.
But numerous minibuses mess this up. First, by widening the distance between the left and right wheels (called the ‘track’ or ‘track width’) they either have to raise the bus and stiffen the suspension so that when the bus leans over in a turn, the wheels do not touch the bodywork of the bus (the wheel arch); or, they take the risk of the wheels actually touching and ‘chocking off’ on the wheel arch in a turn. In every case, the bus now behaves like the stiff-legged lean, and is now completely at the mercy of a roll over.
But that’s not all they do.
Have you ever noticed that the tyres on a truck don’t balloon out the sides of the wheel like those on a car? Truck tyres are made with stiff sidewalls to take the heavy load the truck was made to carry; definitely not for going fast, but the weight of the truck and its load increases its grip. Cars are not expected to carry much weight, so their best tyre is the radial tire (the R in the tyre size written on the sidewall) which balloons out the sides (radially) increasing their contact-patch with the road, especially in a turn, and providing superior cornering stability. By flexing the sides, (put your thumbs together and touch your fingertips, then flex your connected fingertips from left to right) the radial tyre maintains maximum contact-patch with the roadway in a turn. But when the wheel is broader than the tyre à la minibus, the radial effect (spread your thumbs apart and try flexing now) doesn’t work, thus massively increasing the instability of the bus. Further, widened tracks at the front of a vehicle, gives rise to a phenomenon called bump-steer, which, long story short, means difficulty to keep straight over rough surfaces. But there’s more.
The load rating (index) of a tire is written on its sidewall. The best radial tyres the size of which are used on our minibuses, (let’s take Michelin Pilot 195/45/ZR17 a top-brand 17-inch tyre), brand new, each has a load rating of between 80-90. A load rating of 80 means each tire could safely handle 992 lbs. There are four tyres on the bus, so the bus, with four brand-new radial tyres on each wheel, could safely carry 992 x 4=3968 lbs. Now the bus (let’s take a Toyota Hiace typically used in Guyana) without passengers weighs 3500 lbs – 4500 lbs. Add in a driver and 12 passengers at 200 lbs each and the full bus now weighs over 5,500 lbs, clearly way beyond that for which the tyres were manufactured. Overloaded tyres overheat and burst, especially at speed. Now imagine that the tyre is an old ‘dry-rotted’ used tyre while the bus is speeding over Guyana’s potholes daily, and you could predict the propensity of a blowout at speed.
But, just when you thought you could still board that minibus without cold-sweating, it gets worse. Minibuses, born as vans, come with steel rims as wheels. Steel bends upon impact and does not disintegrate like the cheap alloy rims the local bus owners change to. These ‘mag’ rims (a mis-abbreviation for magnesium alloys used for very expensive race wheels and which are completely unsuitable for the road for the same reason), shatter into pieces, upon impact with a curb or pothole, creating sudden deflation or shredding of the tyre, and catastrophic loss of stability and driver control.
Minibuses ought to use truck-type high-load-index tyres, called bias-ply tyres, not radials, on steel rims.
But have you been to Japan, where we get all these buses from? Have you Googled to see whether these minibuses carry people around as public transport there? They most certainly do not. While some mini-vans (not minibuses) were made for family travel just like a car, with individual seats and seatbelts, our minibuses were actually vans, now converted to carry passengers, minus passenger seatbelts, so that suffering third world countries could buy them. In serious accidents the passengers inevitably go flying. Big busses, used in Japan, form bus-type public transport in any developed country, not minibuses.
Minibuses, as operated in Guyana, are therefore patently dangerous and do not belong in the public transportation system. The accident statistics support this, globally.
Mid-sized busses, on the other hand, have diesel engines, that cannot accelerate as fast, or go as fast as the minibuses, but they fetch loads easier and are more efficient doing so; and yes, they have dual, steel wheels with truck tires at the rear to ensure stability and load bearing capacity. In fact, radial tyres won’t even fit on the rear. The dual tyres also prevent a sudden disaster should one blow out. They form a less-than ideal substitute to minibuses.
Solution: phase out minibuses ASAP.
In the meantime, please holler at your minibus driver if he speeds. Take out your phone and record and report the driver to the police. The police should have a whistle-blower programme. Report them to the insurance companies. Studies show that this reduces road fatalities. And, if they kick you out of the bus, at least you’re alive.
Editor, one can write volumes on what is wrong with road safety in Guyana. Pedestrian safety alone would be voluminous, much less drinking and driving. Hopefully in this letter I was able to make my case against the dreaded minibus in favour of bigger busses, and in doing so, I illustrated the need for more meaningful tactics towards the reduction of speeding accidents. Urgent strategic change is necessary.
My heart goes out to the families of the victims.
Yours faithfully,
Keith Evelyn
