Sir, - S. P. Nangle tells us (August 6th) that the way to reduce road deaths is to educate bad drivers, not to "glibly blame 'speeding'."
Working from first principles, some comments come to mind:
(i) It seems reasonable to assume that accidents are more likely to occur immediately after something unexpected has happened. For example, on driving around a corner at an unsafe speed, one is confronted with an oncoming car on the correct side of the road, a lamp-post or the near pavement and an elderly pedestrian right in one's path. In this situation three out of four of the contributing factors to an accident are beyond the control of the driver and an accident is likely to occur.
(ii) As the amount of time required to cover a given distance reduces in proportion to one's speed, available reaction times are reduced in proportion also.
(iii) The available energy in a moving body increases with the square of its speed, i.e., a car moving at 40 mph has four times the energy of a car moving at 20 mph, and a car moving at 60 mph has nine times the energy of a car moving at 20 mph, and thus is nine times harder to stop. Hence, on impact, energy exchanges between vehicles, or vehicles and passengers are much higher than one might think, for a given increase in speed.
Based on the above, if an impact is about to occur, than the vehicles speed is directly related to (a) the likelihood it actually will occur, and (b) the consequential damage to those vehicles and people involved. Empirical evidence seems to bear this out. - Yours, etc., Arthur T. Henry,
Balally Drive,
Dublin 16.