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How to avoid a motorcycle collision

SMIDSY collision high visibility road safety

Ever wondered why people drive right out in front of you and cause a collision?
 They call it “SMIDSY” or “sorry, mate, I didn’t see you” syndrome and they are the biggest cause of motorcycle crashes.

There are a lot of theories about what causes SMIDSY crashes, including saccadic masking (basically gaps in our vision when scanning).

Texas Tech University psychologist Pat DeLucia reckons it is because people think smaller objects are further away than they appear and conversely bigger objects are closer.

SMIDSY crash
SMIDSY crash

Most motorcycles may be small objects on the road, but hardly the Goldwing in the photo above.

I’ve also had a car drive right out in front of me when I was riding a big, bright-orange Harley-Davidson Street Glide.

However, there is a lot that makes sense in Pat’s research.

The Texas Tech psychologist used computer simulation to study participants who viewed two approaching objects simultaneously – one large and one small. The viewer had to nominate which would reach them first.

Her study, “Current Directions in Psychological Science”, indicates that an object’s size affects distance perception, causing drivers to miscalculate riders’ distance and speed.

“People generally picked that simpler heuristic: Larger is closer,” says DeLucia.

Unfortunately, motorcycles are the smallest vehicles on the roads. Even big Goldwings and Harley tourers.

Motorcycles are also the fastest accelerating vehicles on the road.

So drivers think we are going to arrive much later than we actually do.

It’s a lethal combination that could be the cause of up to three out of every four motorcycle accidents.

Ok, so what do we do about it?

  • Having headlights on may make you more visible in some circumstances, but it doesn’t make a difference to the size of your bike.
  • Position on the road is important. You need to ride in the wheel track closer to the centre line as this means you are visible sooner to oncoming traffic or vehicles turning across your path. It also gives you a buffer from vehicles suddenly emerging from a roadside parking bay.
  • Weaving from one wheel track to the other also draws attention. It may look erratic and as though you have lost control, but it attracts much-needed attention.
  • Never assume a driver has seen you.
  • Slow down and get ready to take evasive action if you see a vehicle at an intersection.
  • Wait until you see the whites of their eyes before accelerating. And even then, prepare for them to make a sudden move.
  • If so, it is best to think about changing course behind the car, rather than in front of it. The normal reaction is to weave away from the direction that the threat is coming. However, that leads you into the direction the threat is heading, so you may still collide.
  • If you don’t see the whites of their eyes, then it might be time to give a polite toot on the horn to alert them.

So what happened when the Corolla drove out in front of me?

Harley-Davidson Street Glide - New Zealand -
MBW On a Harley Street Glide

I hadn’t followed any of my own advice and was surprised when I saw the car start to move off.

In panic, I hit the brakes and activated the Harley’s excellent ABS front and rear. Yet I was still able to steer the bike and turn the corner from where the woman was coming. At least I got that part right.

That’s how good ABS can be in an emergency. In a panic stop on a non-ABS bike, the front wheel would have locked and tucked under. The bike would slid straight into the car.

The fact that I could panic-stop and steer at the same time saved my bacon.

I didn’t have the time or awareness to blow the horn and I’m not even sure the driver was even aware of the drama they had just caused as she merrily continued on her way.

  1. There was an earlier study which showed the ability to see was related to the perceived danger. They sent a bike a bike cop and a hells angel with a shotgun on their back down a hwy and counted how many times vehicles intruded into their space. Not much difference between the bike and cop. Guess which recorded zero intrusions!

    1. Ken – that study compared perception of a number of vehicles. “Cop car” rated as highest threat, followed by other cars, closely followed by “cop bike”, then “Bad Boy Harley”, perception/threat then dropped off sharply to leave “standard motorcycle” as least threat/easiest to ignore. My own observations(due to several years commute on the M1) bear this out somewhat.

  2. What happens is called “motion camouflage” – in certain positions on the road as you approach a potential SMIDSY the bike will appear to be motionless and blend in with the background. Even worse – by riding in one wheeltrack or the other your headlight can appear to be part of a car behind you. By weaving you distinguish yourself from the background clutter rather than blending in.

    The research you mention seems to cover the looming effect – objects at a distance appear to remain the same size – when they are quite close they suddenly increase in size rapidly. Another way this can hurt is if the fight-or-flight insinct kicks in – resulting in the driver suddenly slaming on the brakes when they could otherwise have cleared the danger zone..

    1. Yes … a static object against an unchanging background is a recipe for camouflage. Movement is what catches the eye and a rider moving about in their lane is more likely to be seen. We still must take steps to be prepared to stop if necessary. Understanding the physical limitations of human eyesight and reactions can help us as riders navigate the hazards 🙂

  3. When I do drive my car, a three year old Lancer I am really aware of riders being one myself but I do think the newer style side mirrors on cars play a big role as the project those behind as being much further away and until you glance in the rear vision mirror you could pull out in front of a bike, or car thinking they are much further behind. I hate the side mirrors on my car and feel on dual carriageways they are downright dangerous.

  4. Two Wheels Magazine de bunked a lot of theories a few years ago with a simple experiment , they sent out 3 bikes on the same route , same time of day and same riding/ visability conditions for a week. 1st was a guy on a postie bike in high vis, second was a sports bike in leathers and third was a large guy on a Harley in biker dress. Results were postie bike ran off twice , several near misses, Sports bike a couple of near misses and lastly Harley man with no problems to report . A simple case of repercussions , chances of getting physically assaulted by any of the three test bikes showed a clear result . Drivers do sometimes not see a rider but more than often don’t give a shit what happens to the rider if they cut them off / pull out in front or show no regard for the rider. Case in point. bicycle riders are fare game to a percentage of drivers. Another point I have been called a “temporary Australian by Police and Ambos. Now with mobile phones and other tech distractions in cars the odds are even worse!!!!

  5. its hard to see the white of their eyes with tinted windscreen, most of the time you can t see if someone is in the car. I nearly got hit by my neighbour taking off without indicator as I was turning into my home and indicating doing so.

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