[WARNING this blog entry is really boring. I thought I had an interesting perspective to put, but I was nearly asleep by the time I'd finished writing. But finish I did, and I was damned if I'd just throw it away, no matter HOW devoid of merit it might be]

My Spitfire has brakes! I didn’t know this, but the brakes are capable of working nearly 50% more effectively than they have for the past year. I know this because they now do. My first 6 cars having been minis, most more than 15 years old at the time of purchase, I fully accept that older cars’ brakes were not as effective - even when new - as modern cars’. For this reason, I was not unduly concerned that in the spitfire you generally had to plan your emergency stops and use the engine to dump a significant proportion of your speed. The great thing I discovered was how much more sensible my driving was because of it.

I reckon good brakes are the indirect cause of many accidents today. By causing me to habitually drive with more caution, I am likely to get longer to react and be travelling slower by the time any real danger is present.

Picture a row of cars each driving as close as they dare to the car in front. Each driver thinks “the chances are the driver in front won’t brake, unless he meets an obstacle”. Driver 1 brakes. Driver 2 takes a moment to notice and be surprised by this before braking. Because of this delay, driver 2 needs to brake harder. Each driver takes a moment to spot the emergency, then needs to brake a little harder than the one in front. Some driver down the line can’t stop in time and nudges the previous driver into the one in front. Three-car shunt.

Of course there are other factors like many drivers are smart enough to look a few cars ahead and on observing the brake lights will back off and create a safety zone. But many don’t.

In a car with less effective brakes, the brake lights still come on when I press the pedal, but the change I introduce to the situation is less, i.e. I don’t slow down as much. This can be an issue for me if I’m behind an ABS’d up M3, and I might have to bring the steering into the equation, but for the person behind me, there is more time to react and less reaction needed. The rate of change of the situation is slower, though the brake lights, the warning of the change, come on just as early. Thus the mean advance warning is greater and average seriousness of accidents is reduced.

To me, safety with humans in the loop is not directly about keeping speed down. It’s about maximising the time between perception of an issue, and the deadline for judging how to deal with the issue. Of course, the higher the speed the lower this time in general, but there are other factors too, like:

• earlier warnings
• looking ahead
• gentler manoevring
• larger spaces

Just because your car can stop in half a second doesn’t mean you can stop it in half a second.