Defensive Driving – the definitive facts

Defensive Driving - the definitive facts




So just what is Defensive Driving?  The name crops up in lots of web sites and in lots of other publications. But what does it actually mean? Many sources give a very vague definition if at all, others get it quite wrong. Even the NSC (USA), where the term originated, now offer a definition that is a long way from their own original concept, and not safe. The UK Highway Code doesn't mention defensive driving at all; nor does Roadcraft the Police driving manual. The UK DSA in their 'Driving the essential skills' gets close to a definition of Defensive Driving with "… The better you control your vehicle and roadspace the safer you will be."


Defensive Driving ranks alongside Eco-driving, Safe driving, Advanced driving, Performance driving, Response driving, Tactical driving, Evasive driving, Pursuit driving, Convoy driving, and others, as a style of driving employing specific skills or techniques to accomplish a specific outcome. Unfortunately, there are even two distinct and different forms of Defensive Driving that share the same name: (a) defensive driving as in defending oneself from attack, i.e. defending against risk of kidnap or assassination, and (b) defending one's vehicle against risk of collision. These two variations share some similarities, but are very different in other respects. It is only this latter form of defensive driving that shall be considered here - defending one's vehicle against risk of collision.


So why the name 'Defensive'?  Its origin goes back many decades to the early 1960s, and is linked to the principle of defending the space around one's vehicle, i.e. merely controlling space, but of course 'controlled' driving would never have had the same ring to it.


So what is Defensive driving, and what is it not? There are many aspects of safe driving that are not related to defensive driving whatsoever, and other areas that are only related indirectly.

For example, a typical corporate Defensive driving day normally commences with the vehicle checks, and whilst these are very valuable and certainly an important part of safe driving reducing all types of personal and vehicular risk, they have nothing directly to do with the essence of maintaining space, so are not actually a part of defensive driving. Whilst checking e.g. the engine oil is a vital part of safe driving, the fact that if there was insufficient oil and the engine seized, would not necessarily mean we would become too close to another vehicle or fixed object and crash; we should still be able to stop in a reasonably controlled manner.


Legal compliance as we all know is essential in all aspects of driving, and whilst some laws are written for revenue generation, a few merely for enumerative purposes, many laws are written purely for safety purposes. Whilst no-one should condone any traffic violation, it is nevertheless a fact that failing to comply with the law may not in itself mean a person was driving un-defensively. For example, exceeding the speed limit on an empty road is certainly an offence, and in many cases may also be very unsafe, but in some cases it may not necessarily be un-defensive.


Good observation, use of mirrors, signalling, and a thousand other aspects of car control may if done correctly contribute towards Defensive driving, but are NOT a constituent part of it. For example, a driver may be excellent in all his observations, car control, and other aspects of driving, but if he is also tailgating, then he is certainly NOT driving defensively.


So what is defensive driving?  As mentioned above, it is merely defending against risk of any type of collision; driving in such a manner as not to (i) cause a crash ourselves, and (ii) avoid the risk of becoming involved in someone else's crash. This includes reducing the risk of being hit from behind.


Let's go back to basics for a moment. Any collision only occurs when our vehicle becomes too close to another vehicle, person, animal, fixed object, or in the case of a roll-over: the ground, such that the space between our vehicle and the other surface reduces to zero or less. If we can always maintain a safe space around our vehicle then it is impossible to ever suffer a crash. In the last 140 years of the motor vehicle, no-one has ever collided with a space.


To achieve Defensive Driving we have four important rules for maintaining space -

The primary rule to protect the front and rear of our vehicle whilst moving must certainly be the '2-Second Rule', adding additional seconds as necessary to match degraded environmental conditions.



Secondly we must also maintain safe space at the sides of our vehicle - the 'Doors Width Rule' and its proportionate multiples depending upon our speed when passing stationary objects.



Thirdly for maintaining space is the 'Diagonal Rule' and which states "Always position yourself DIAGONALLY to other vehicles, when travelling in a multilane system at a similar speed to other traffic", i.e. don't travel alongside another vehicle which is steering, or which may steer, as you may come into contact.



And fourthly, to protect our front & rear when stationary we have the 'Queueing Distance Rule'. This certainly raises many interesting points. Most driving instructors worldwide teach that when stopping in a traffic queue, it is sufficient that the driver behind can see the rear tyres of the car ahead, but as the bonnet of a modern car is shorter than many years ago, and on most cars the bonnet slopes down quite steeply, this may now only give a gap of about 2 metres, whereas previously it would have been longer. I sometimes wonder what instructors say when their pupil is stopping in a queue behind a bus or lorry having a long rear overhang, i.e. where the rear wheels are 3 metres from the rear end, clearly the usual phrase of 'tyres on tarmac' is insufficient.



However, it is this Queueing Distance Rule where there is the major difference between Learner driving and Defensive driving. See here for the Queueing Distance Rule.


So as a summary, Defensive Driving is not about the vehicle itself, neither its condition nor how it is used. Defensive Driving is not about the quality or absence of observation or signalling, and it's not about speed, or compliance with the law. Defensive Driving is not about the weather, the road surface, or other environmental conditions, and it's not about the physiological condition of the driver, or actual or potential hazards that arise - none of those things.


Defensive Driving is all about using just 4 rules to maintain a SAFE SPACE.



© Keith Lane B.Sc.DE. 2008