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Thoughts on SMIDSY accidents

SMIDSY Accidents

I was browsing on Visordown earlier and one of the usual discussions has been maturing nicely into the value of hi-vis clothing and daytime lights.

Horse notes: “Most SMIDYs happen in urban situations, when the bike is travelling at 30 or under. The ‘at risk’ zone is just 3 seconds long. If someone doesn’t see a bike & rider 3 seconds away, it’s not because of a lack of hi-viz, it’s simply because the driver didn’t look.”

I like this way of thinking…

…though of course there’s also the “looked in the wrong place” explanation – research shows that experienced drivers look down the road directly to where they want to find a gap and don’t scan across the zone closer to them. And there is also the “looked but didn’t see” reason, where something was in the way or drew the driver’s attention.

It’s definitely worth emphasising the effect of slowing and reducing momentum, and removing recognition and reaction time from the equation. From 25mph, if you have set the bike up on the brakes by applying them lightly before you need them in anger, you can stop in three bike lengths! Even at 35 it’s only 6 bike lengths, MUCH less than most people would say you need for an emergency stop, but it’s because you remove reaction and set-up time.

Whereas if you are expecting your hi vis kit and lights to stop a driver in their tracks, and thus aren’t on the ball looking for an accident waiting to happen at every junction, you won’t be on the ball. In this condition, it can take up to 3 seconds from the moment the Mid-brain wakes up from its ‘relaxed awake’ state to an ‘attention-demanding reaction time task’ for the decision making Neo-cortex (thinking brain) to actually process the visual information it’s receiving, work out what is happening, decide on a course of action and actually activate the muscles.

3 seconds? Isn’t that where we came in? Proactive responses to the risk of a SMIDSY by the rider narrow the killing zone to virtually nothing, and are far more reliable than hoping someone might see you and not pull out.

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