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Steer with handlebars    Bike Crash Evasion and Mitigation

By the time we get here, hopefully we're ready with the advanced riding skills we learned while training, and the mental road picture we created while riding ultra-defensively prior to the crash causation.Britten bike

This is not quite enough. The skills we learned in training classes won't avail us if we haven't been practicing them.

The best thing you can do to keep your crash evasion skills current, between classes, by periodic practice.

Going down, down, down, down.

Track racers, who go down all the time, but are athletic, have nerves of steel, are skilled, possessed of youthful reaction times, are wearing great protective gear and are on a track where the worst obstacle is a hay bale, are often scared of riding on the road, and with good reason.

The adrenalin rush that comes with impending danger is powerful. Time is slowed down and you see events as a series of freeze-frame moments. There may be time to deploy whatever skills you have been practicing, and whatever strategies you have thought about in advance. There is very limited time to make stuff up on the fly.

Many crashes unfold in two seconds or less. You hopefully have good situational awareness, because you have been driving defensively. You have been predicting possible outcomes from the current traffic situation and have given yourself the maximum possible reaction time by foreseeing problems early. You have also been monitoring possible escape paths. You may have adjusted your speed or lane position when approaching the problem, or covered the brakes, (giving you a sixth of a second off your reaction time if you choose to brake.

You have also been preparing strategies, have studied the various evasion and correction options, and have a menu of moves previously thought out and ready to go.

The impossible happens, the adrenalin kicks in, and you have one chance to deploy the right evasion tactic. Maybe you'll live.

Thailand Study and Evasion

The Thailand study found that:

...(There were) 379 cases in which both proper choice and proper execution of the evasive action were evaluated. Only one third of riders who took evasive action (19% of the 723 cases) made the proper choice. About 39% of those who took evasive action (20% of the 723 cases) executed their chosen evasive action properly. Only 12% of those who took evasive action (6% of the 723 cases) chose the proper evasive action and executed it properly. - Motorcycle Accident Causation And Identification Of Countermeasures In Thailand, Volume 1, Vira Kasantikul, 2001.

The report identified an additional 431 cases where a detection or decision failure occurred, and no evasion was done as a result. In many cases, there was no time for evasion, which may be the result of inadequate situational awareness, but sometimes was not predictable. An example of this was when a cage crashed with another vehicle and careened into the motorcycle.

Other studies, including Hurt and Maids, identified skills deficits of a similar nature which limited effective crash avoidance. Thailand had no civilian motorcycle training courses at the time of the study, and only one rider in the Bangkok study had had formal training. In Maids, riders with more training were more likely to attempt an evasion.

We also note that the study methodology focuses on injury crashes, so evasive actions implemented correctly, avoiding a crash, would often not be reported. Selecting the right evasion and executing it right can keep you out of the stats.

We conclude that having the right skills and making the right decision on evasion is a rare set of skills worth acquiring.

Evasion Possibilities.

We have two basic evasion techniques, swerving and emergency braking. There are a few other possibilities, including putting the bike down in very limited situations, baling out in even more limited situations, accelerating away from a problem, and some techniques for dealing with bike issues, including tire deflation and weave or wobble situations.

Swerving plays to the bike's strengths, maneuverability and narrowness, but it is performed at a constant speed, so if it fails and you impact, it may be at a higher speed than if you did a quick stop.

Braking has advantages also, especially by reducing impact speed if the maneuver is unsuccessful. If successful, the motorcycle is still in the traffic lane ready to continue. Overbraking a wheel can cause a potentially risky skid, which is a frequent cause of putting the bike down.

This paper examines the effectiveness of swerving versus braking for obstacle avoidance, and it looks like, unless you have ABS or are a very experienced rider capable of attaining -0.8G braking force, that you wheels clear a ground obstacle quicker via a swerve than via braking, and this advantage starts at or under 35MPH for average riders (-0.6G average braking force) and increases with greater speed.

Decision Time

Roadcraft estimates reaction time as 0.7 of a second. That's about one foot of roadway for every mile per hour. Here's our following distance page.

(1) Have you been driving defensively and is there an escape route that you have been monitoring? This may be an empty lane to either side, a hard shoulder or a large gap between slower-moving traffic in adjacent lanes.

Is there sufficient space to swerve and clear the obstacle? Am I less experienced or traveling over 40 MPH or are there traction issues for braking?

Consider a swerve.

If a swerve puts you on the shoulder, stop and check your tires as soon as is practical. Some shoulders have a lot of debris that can damage your tires. You should preferably not brake prior to or during a swerve, but if you have practiced swerving with a small amount of rear braking and need to slow a little, you could do a small amount of rear trail braking.

(2) Is bike is currently stable (straight up, no sliding, no mechanical issue)? Is there enough space to stop if the problem is that the vehicle ahead has suddenly stopped?

Consider emergency braking.

If you want to swerve and brake, consider doing the swerve first. If you brake before swerving, your front suspension is down, or compressed, and your rear suspension is up. Performing a swerve with your suspension set after braking makes the swerve more likely to be unstable if your wheels hit a pothole or bump.

Immediately on completing emergency braking, threats from the rear become the major potential problem, so despite the dramatic effects of adrenalin, attention should be focused on the mirrors and rear observation and getting in the right gear for an immediate evasion.

(3) Is there a bike mechanical or stability issue?

On a turn and stable? Consider straightening and emergency braking . If you can't straighten and stop in the space available, your best bet might be to modify the turn into a swerve.

Wobble or weave? Check out the wobble/weave correction

Tire or catastrophic suspension or frame problem, weather issue, obstacles, loose surfaces or debris? See other evasion issues.

(4) Is there a situation that suggests baling?

Rear-enders are often lethal to bikers, although they are a minority of crashes. When stationary in traffic or after an emergency stop they become the most likely threat, demanding additional rear observation in the later stages of braking and when stopped.

You are stopped or very slow, and are prevented from riding forward or to the side to avoid an approaching rear-ender? You might not be able to move because of a red light or because there isn't time to accelerate away.

Consider baling out to the side that is safest. This would be a last resort in a dire emergency situation.

Ideally, being able to accelerate away from an impending rear-ender would be better, but is sometimes not possible. This is why emergency braking practice has such emphasis on being in the right gear.

In circumstances where it is possible, accelarating away from a threat, such as a cager on a highway ramp, is something bikes do well.

(5) Is there a situation that suggests putting the bike down?

Putting the bike down is the excuse often given by poorly skilled bikers to explain why they skidded during emergency braking or just panicked. But there are some rare situations where it may be the least bad option.

If it's a low-side situation (e.g. a lateral front-wheel skid in a turn)? Some low-side situations are reversible, but a failed attempt to correct a low-side might put you straight into a high-side, which is generally more dangerous. There is no natural stopping point when correcting a lateral skid, for example. If you judge that a high-side is likely if you correct the impending low-side, the low-side might be preferable.

If you are running off the road in a turn and there is an obstacle, like a guard rail, in your path you are likely to be thrown or to incur a severe (but probably not life-threatening) leg injury. If to be thrown means going over a cliff or into water, putting the bike down and sliding or rolling to a halt, assuming you are not going into the path or traffic or towards a curb or immovable object, might reduce injury. This is always a crap-shoot.

We usually like to kick away from the bike and tuck in, hoping to slide or roll to a stop without crapping out on a kerb, vehicle or furniture.

If you are going under an obstacle like an 18-wheeler or a wide load, maybe putting down is an option.

Stayin safe blog on dropping the bike in an emergency.

Avoiding highsides from MSGROUP.ORG.

(6) You got here? Not your lucky day. Back to (1) and not so choosy next time. Go with your instincts, that is all you have left.


Multi-vehicle accidents.

A lot depends on how well you've been tracking traffic. You should, after practicing the techniques in ultra-defensive riding, be ready with a good model of the current road situation and an escape route ready to go. Hopefully, you'll also have created a tiny time window to act in, by successfully scanning and evaluating problems early. Then it's a case of immediately deploying an evasion based on what you already know about the traffic situation. There are some useful links below on the evasion maneuvers.

Single-vehicle crashes.

The most common single-bike crash is the bike running off the road on a turn, other causations are discussed in the links below. Training and skills practice are again the best way to avoid and mitigate these accidents. Some accidents are caused by road conditions, e.g. gravel and debris in the road. The links discuss skills for this type of crash mitigation.

Better Motorcycling on safe cornering

Allexperts.com on gravel in a turn.

Further Reading

Better Motorcycling on riding out a rear wheel skid

MSgroup.org on countersteering (best explanation we've seen)

Better Motorcycling on safe cornering

Better Motorcycling on correcting weave and wobble

Better Motorcycling on tire grip variation while maneuvering

Motorcyclecruiser.com on emergency braking research and the benefits of ABS

Youtube: Canadian PSA on stopping in emergency

Stayin safe blog on dropping the bike in an emergency.

Avoiding highsides from MSGROUP.ORG.

Allexperts.com on gravel in a turn.