Every couple of years, the discussion on increasing the speed limit in Bermuda is rekindled.

Any number of imaginative reasons are invoked for driving faster on our narrow roads, some holding a grain of truth, most well meant, and others resulting from truly faulty logic.

Some have suggested, for example, that those who drive at 35 or 40 kph are responsible for a significant number of crashes as a result of following vehicles trying to pass them. A guy who's "makin' time" because he woke up late gets impatient and starts passing dangerously and crashes?and you blame it on the driver who is law abiding? Get real.

Others are under the impression that increasing the speed limit will somehow alleviate our traffic congestion problem. No way. We simply have too many vehicles on the Island and too few people willing to car pool, get smaller cars or use the ferries and buses.

I've also heard the argument that since most people are driving at 50 kph anyway, we should just increase the limit to 50 kph and really, really enforce it.

Driving at 50 kph is 42 percent over the current limit (most jurisdictions tolerate ten percent) and there is no reason to believe that with the limit set at 50 kph, folks would not try to do 70 kph ? and it would be na?ve to believe that enforcement will somehow just start working (because it sure doesn't now).

I'm all for speed cams (set at ten percent above the posted limit, say 40 kph) but they've been on the books for a very long time and I wouldn't hold my breath waiting for them. In any case, just come spend an evening in the emergency room to see the carnage first hand and then we'll talk about raising the limit.

Now, consider the following before pushing for an increased speed limit. First, there's nowhere to go on our small island. Let me explain. The travelling distance between Somerset and Hamilton is about 15 kilometres. If you could drive at a steady speed of 40 kph the whole way, it would take you just over 20 minutes. If you increased your speed to 50 kph, you would get there just four minutes faster (I'll be comparing these two speeds throughout).

The same comparison from St. George's to Hamilton, a drive of just over 13 kilometres, also saves you about four minutes. Four minutes. Big deal. Now what else happens when you drive at 50 kph instead of 40 kph? The really bad news is that your total stopping distance increases dramatically. For the average car, the stopping distance at 40 kph is around 17 metres, and at 50 kph, 24 metres.

For all you engineers out there, these estimates take into account perception time, physical reaction time, vehicle and road factors and assume new tyres, a dry surface and a coefficient of friction of 0.7. The numbers are much scarier for worn tyres on wet pavement. That's an increase of seven metres and it's not something I can live with (pardon the pun).

Your vehicle in motion possesses something called kinetic energy ? my little Daihatsu Charade weights in at about 750 kilograms and boasts around 46,203 Joules of kinetic energy (K= mv2 for those who are interested) at 40 kph. God knows what it is for a bus!

Increase the speed by a mere 10 kph and my hatchback now packs a punch of 72,453 Joules, a 57 percent increase! Now when my vehicle comes into contact with a solid object, the energy is converted into , and again, I invite you to our emergency room too see the results of that when the object is a person.

I'll spare you the physics describing the difference in energy dissipation between a head-on collision at 40 kph and one at 50 kph which is a real concern on undivided roads. Do we really want to increase those large chunks of kinetic energy flying around on our roads by an average of 57 percent? Not on my watch.

Another one I hear frequently is "Why don't we just increase the speed limit on selected stretches of road, say Kindley Field Road?"

I recently attended the Sixth World Conference on Injury Prevention and Control where a number of papers were presented on the very topic.

Here's what they found: increase the speed on some selected roads and you immediately see a phenomenon called "speed spillover" whereby the average driving speed increases on all other roads.

The more important finding, however, is that small increases in speed (say ten percent) lead to an abrupt increase in deaths (24 percent in the example I'm quoting) and case fatality (the percent of crash victims who die, 29.5 percent in this case) on all roads.

The rise in case fatality is directly attributable to increased speeds of impact and obeys closely predictive models showing a fourth power relationship between rises in travel speeds and case fatality.

Finally, I would like all you aspiring NASCAR drivers out there to realise one thing: You're not on a race track! The roads are for everyone including walkers, runners, cyclists and mothers pushing strollers (maybe with child in one).

Their lives are in your hands. You, the driver, has the far greater burden of responsibility because you're the one with the dangerous weapon.

We live in one of the most beautiful countries in the world. Slow down, smell the roses and drive responsibly. Your life (and mine) may depend on it.