Monday, April 11, 2016

Time exposed to danger.

A few weeks ago I was talking to a colleague about the merits of better driver training and the subject of 'time exposed to danger' came up (referred to from hereon as TETD). In some countries, this is part of driver training. In the U.S it isn't. The principle is simple - when you're going to make a maneuver whilst driving, you should minimise your TETD. What does this mean?
Take a simple example: you're on a motorway, coming up to a semi / articulated truck, and you want to pass. To minimise your TETD, the best option is to hold back until the entire lane next to the truck is clear, then pull out, pass quickly, and pull back in far enough in front so as not to cause the truck to need to slow down. The worst option is to set your cruise control / right foot to 2km/h faster than the truck, pull out and spend 30 seconds slowly overtaking. Trucks are big, the maneuver slow, they are riddled with blind spots and they do a lot of damage. The last thing you should be doing is dawdling next to one. Doubly so if you're on a motorbike. Your safest bet is to pass quickly, in one go.
The same is true in urban areas. If you're sitting in a side street waiting to join a main road, to minimise your TETD you should pull out and quickly accelerate up to the speed of the rest of the traffic, thus creating the minimum impediment for other road users. The worst option is to pull out slowly, then gently idle up to the speed limit. By doing this, you're taking longer to reach the average speed of the rest of the traffic, and the speed differential in this case is your exposure to danger. By accelerating smartly, you quickly reach the same speed as everyone else and your time spent as a 'rock in the stream' is vastly reduced.
Similarly if you're on a narrow road wanting to pass a cyclist, don't dawdle past him, nervously crossing the center painted line. Wait for the oncoming traffic to clear, and pass quickly. Instead of spending 20 seconds 'sort of' in oncoming traffic, straddling the line, you spend 2 seconds in the other lane then pull back in.
Finally - and this might seem like it's a bit out of the left field - consider your options if you live in an earthquake zone. Let's say you're in a line of traffic queued up under a motorway, waiting for the lights to change so you can turn and head up the on-ramp. To minimise your TETD, you would ideally wait with clear sky above you, even if this means leaving a gap to the traffic in front. When the lights change, accelerate under the overpass and around to the on-ramp. In an earthquake zone, the worst option is to wait underneath the overpass because should the worst happen, you're stuck in a line of parked traffic with a couple of hundred tons of concrete, rebar, trucks, trains and cars over your head, and the 3mm of pressed steel in your roof won't stop you from becoming a smear of jam when the overpass collapses.
So consider your time exposed to danger next time you're passing a three-trailer delivery truck with your cruise control set to 1km/h faster than him.