What is a SMIDSY?
Understanding One of the Biggest Threats to Motorcyclists
If you've been riding for a while, you've probably experienced that heart-stopping moment when a car pulls out in front of you as if you don’t even exist. This is what riders commonly call a SMIDSY—short for “Sorry Mate, I Didn’t See You.”
SMIDSY incidents are a major cause of motorcycle collisions, and if you’ve ever attended a Biker Down course, you’ll know that understanding why they happen is crucial to avoiding them. Let’s break down why SMIDSY crashes occur and how advanced riders can reduce the risk through better roadcraft.
Why Do SMIDSY Collisions Happen?
A SMIDSY typically happens when another road user fails to spot an approaching motorcyclist at junctions, roundabouts, or when changing lanes. But why do so many drivers “miss” motorcycles that are clearly there?
1. Motion Camouflage
Human vision is wired to detect larger, fast-moving objects. A motorcycle, with its narrow frontal profile, can blend into the background, especially against a cluttered urban environment. This effect, known as motion camouflage, makes it harder for drivers to gauge your approach speed.
💡 Advanced riding tip: Use lateral movement before reaching a junction to create optical flow—this makes it easier for other road users to detect you.
2. Looked But Failed to See (LBFTS)
Many drivers genuinely look in the direction of an oncoming motorcyclist but don’t register them. This is a cognitive issue, not just a visual one. Car drivers expect to see larger vehicles like buses and trucks, so they may unintentionally filter out smaller ones.
💡 Advanced riding tip: Position yourself where you expect drivers to be looking—often near the A-pillar of a car rather than directly in the centre of their vision.
3. The “Saccadic Masking” Effect
The human eye doesn’t scan smoothly—it jumps between focal points, a process called saccadic movement. If a motorcycle is in a "blind spot" between eye movements, it can be invisible for a crucial moment when a driver makes a decision.
💡 Advanced riding tip: Headlight modulation and high-visibility gear can make you more noticeable, but smart positioning is even more important.
4. Misjudging Speed and Distance
Because motorcycles are small, drivers often underestimate their speed and distance. This is why many SMIDSY incidents happen when a car pulls out, thinking they have enough time.
💡 Advanced riding tip: Always be ready for cover braking (a light touch on the brake lever to prepare for rapid stopping), and consider a slight throttle roll-off near junctions to increase your visibility.
Other Common Causes of Motorcycle Collisions (From Biker Down Experts)
The Biker Down initiative, run by emergency services and motorcycle safety experts, has highlighted key factors in motorcycle crashes. Understanding these risks is essential for advanced riders.
1. Right of Way Violations (Junction Collisions) Most motorcycle crashes happen at junctions, where a car driver either misjudges or fails to see the rider. This is the classic SMIDSY scenario.
💡 Advanced riding tip: Use the Lifesaver shoulder check before committing to any move. If you’re unsure, slow down and prepare to react.
2. Loss of Control in Bends A significant number of motorcyclists crash due to entering a bend too fast and running wide. Panic braking in a corner can cause loss of grip and lead to a low-side or high-side crash.
💡 Advanced riding tip: Always use the Limit Point Analysis technique to judge your speed and adjust smoothly as you approach a bend.
3. Filtering Accidents Filtering through slow-moving traffic is legal but can be risky if drivers change lanes unexpectedly. Many filtering collisions happen when a driver fails to check mirrors or blind spots.
💡 Advanced riding tip: When filtering, reduce speed differential, watch for wheel movement (a sign a car may change lanes), and always have an escape route planned.
4. Rear-End Shunts Being rear-ended is a risk when stopping in traffic, especially at junctions or pedestrian crossings.
💡 Advanced riding tip: When stopping, leave space ahead, stay in gear, and pulse your brake light to make yourself more visible.
How to Avoid Becoming a SMIDSY Statistic
By applying advanced riding techniques and understanding human vision limitations, you can significantly reduce your risk of being caught in a SMIDSY incident.
✅ Use the OAP System (Observation, Anticipation, Planning)
Spot potential SMIDSY scenarios early and plan for them.
✅ Make Yourself More Visible
Strategic positioning, subtle speed adjustments, and lateral movement can break motion camouflage.
✅ Be Ready to React
Always assume that you haven’t been seen—cover the brakes and adjust your speed if necessary.
✅ Invest in Advanced Training
At Enhanced-Rider.com, we teach real-world defensive riding strategies to help you ride safer, smoother, and smarter.
Book Your Advanced Motorcycle Training Today
If you want to reduce your risk, improve your riding, and ride with more confidence and control, our expert training at Enhanced-Rider.com is the next step.
📅 Book a session today and learn how to avoid SMIDSY incidents, improve your hazard perception, and master real-world roadcraft.
👉 Visit Enhanced-Rider.com or call us to get started!
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