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A Real Life Example of a Motorcycle reaction Accident Reconstruction

A Real Life Example of a Motorcycle reaction Accident Reconstruction


This video will explain human factors
through the use of a real crash. This real life example involves a car versus
a motorcycle crash that happened on a four lane road with a grassy median in the middle
of the Northbound and Southbound lanes. Unfortunately, this example is just one
of many that happens far too often. In this example the Biker’s name was James. It was a clear Sunday morning. A red car is northbound, and wants to turn left
to head West into a Starbucks parking lot. The red car pulls into the middle turning
area waiting for traffic to clear. At the same time a southbound blue car enters
the same median area to make a left turn. As the two cars are in the median, they are obstructing
each other’s view of the oncoming traffic to some extent. The red car thinks that oncoming traffic
is clear and that he can turn left, but he fails to see James on his motorcycle heading
South at approximately 40 miles per hour. The red car starts his
improper turn, violating James’s right of way by
entering into his lane. A crash is going to happen. Let’s break it down and look at it from a human
factors physics and scientific perspective. James will Identify the threat. He is in his lane, driving South His
focus is on his lane ahead of him. He will be aware of the other
vehicles in the median. So far, he is not perceiving or
identifying any sort of threat. However, as soon as he detects
the motion of a vehicle coming into his lane, he will immediately
identify that threat. He will be keenly aware of the motion
and size of the car entering his lane. In this case, James will identify the threat
well before the driver of the car will. The car did not see the
James at all, otherwise, he would not have begun his turn into James’s lane. At this point in time, James
has Identified the threat. Let’s move to the second step and that’s
all motorcycle riders will experience. And that is James must now Predict the Outcome. He has identified the threat, and now in his mind
he will predict that a collision is imminent. He predicts that his lane
will be completely blocked by the car making a left turn in front of him. James predicts that after
considering his speed and the speed of the turning car, that there
is no way to avoid an impact. James predicts that an impact is unavoidable. He must now go to the third step and
that is to make an instant decision about what to do to avoid, or reduce
the damages of the impending crash. What shall James do to avoid or reduce the
imminent crash that is about to happen? He must make a snap decision about
what action or maneuver to take. Let’s consider James’ Choices about what he can
do to avoid or lessen the damages from the crash. He only has two choices. First is Speed, and the second is direction. There are no other options. And There are essentially nine
evasive actions that James can take. Three with speed, which are to brake to reduce
speed, maintain speed, or to accelerate. And James has three choices with direction,
turn Left, go Straight or turn Right. James first option is to change his speed. Option one, speed up, and try
to make it past the car. This choice is a tough one, and
one that is not a natural choice. The normal human reaction is to
avoid a collision by attempting to stop rather than accelerating
towards the threat. For the sake of this example, if James were to
accelerate, he increases the amount of energy that will transfer into his bike and his body if a
collision happens and injure himself more severely. This is a highly unlikely choice
and is a very bad decision. The more likely choice and safer
decision is to reduce his speed and decrease the amount of energy
that the impact will have. So in this example, James
will apply his brakes as hard as he can while maintaining
control of his bike The second maneuver option after
changing his speed is to change direction of the bike, to start
a turn to avoid the crash. This is a good decision for James
if he is a skilled rider with lots of practice of braking
while turning at the same time. His choices are to either change his direction
to his left, go straight, or turn to his right. In this example, the safest and most
common turning decision would be to turn towards the right in an
attempt to avoid the whole impact. James might get lucky and the car
driver might suddenly see him and slam on his brakes and James is able
to go around the car completely. However, this decision to swerve
to the right has other risks. There may be traffic to his
right, James may be turning into another dangerous situation
by going to his right. Does James have time to look to his right? Not likely. But if he is keenly aware of the traffic
situation he may choose this evasive maneuver. Back to our example, if the car does not stop, and James
turns to his right, at least he will to some extent lessen the impact by hitting the front of the car with his
bike and having his body go over the hood of the car. If James chooses instead to go straight,
he will likely hit the “B” pillar of the car with his face and his body, and
likely become catastrophically injured. If he swerves to his left, then he hits the
passenger side of the car, and his face contacts the roof rail of the car, again causing
possible catastrophic injuries or death. Now, let’s go back to his decision
to change his speed by braking hard. Is braking a good choice? If James chose to go straight,
then braking is the absolute best choice to make because
it will lessen the impact. But if James makes an evasive turn to the right,
AND at the same time attempts to brake, then he runs the risk of exceeding the laws
of inertia and starting a skid or a slide because his tires will lose contact with the road,
and not reduce his speed as effectively. If this happens he is not slowing as much as he
could if he maintained full braking control, and he is not turning away from the collision
due to the lack of tire contact with the road. Like I said, This is an extremely dangerous
combination of evasive moves where he is likely to lose control of his bike, and possibly go under
the car and face catastrophic injuries or death. The safest maneuver is to brake hard and not turn. Braking hard and turning at the
same time is very dangerous. Now, Should James use both brakes, the front
wheel and the back wheel at the same time? Yes! We know the front brake is
more powerful than the rear due to laws of physics caused
by the weight transfer. However, he should use the back brake at the same
time to do everything he can to reduce his speed. Sliding is the biggest risk
James faces in this situation. He is applying full brake power and taking an
evasive turn to the right at the same time. He can easily cross the 100 percent traction
limit, start to skid, lose control of the bike and go down where he is at greater
risk of catastrophic injury and death. Now let’s talk about how fast all
of these things happen in time. As we discussed, James has to
First Perceive the danger. He has to see the red car coming into his lane and
he must perceive this as a danger to himself. Human perception takes time
before any reaction can occur. Reaction times for the human brain are
estimated to take approximately 1.75 seconds, depending on various factors such
as health, age and time of day. This is the time the average
human brain will take after seeing a danger, to actually react to the danger. In this situation James will perceive the
danger and one and three quarter seconds later begin his evasive maneuvers by applying his
brakes and or starting an evasive turn. Now, we need to consider how a motorcycle turns. A motorcycle takes about 1 second to begin a turn. This is because you have to lean the
bike first, before a turn can happen. It takes about one to 1.5 seconds to
turn 1 foot depending on your speed. So we have a time lag of about
two and three quarters of a second from Perception, Response,
to Execution of the turn. So, let’s back up 1 second to turn, and back up another one point seven five
seconds to perceive that you need to turn. This means that it takes two point
seven five seconds from perception of the danger to taking evasive action
to turn the bike away from the crash. Remember that James could see the car before the
car could see James, because the hood of the car is coming into James path of travel, James is focusing
on the unexpected intrusion of the car into his path. It is a clear and present danger to his safety. Now Let’s switch places for
a second and consider that the car will see James in
time to avoid the crash. What is the car’s perception response
and execution of braking likely to be? The perception of the car
driver initiating the turn is expected to be much slower than
James’s for a few reasons. First, the red car obviously did not see
James, so he is committed to his turn. And it is unlikely that the red
car will be able to perceive the risk of collision quickly
enough to slow or stop his car. His perception time is going to be
in the two second range, followed by one and a half seconds to decide to
brake and then slam on the brakes. Let’s consider the physics
of speed in this example. If James is going 40 miles per hour,
he is covering 58.33 feet per second. Let’s see how far away he
would have to be to apply his brakes at a perfect 100% to
stop before hitting the car. If we assume that the roads are perfectly dry, and that his
tires are in excellent condition, then we use a co-efficient of friction factor of .7, this tells us that
making a perfect 100% full stop going straight, James can stop in 59 feet. Now, if we back up 1.75 seconds to allow
James time to perceive, predict, decide and then to execute an avoidance maneuver, which is going to be to apply
his brakes at 100% braking, then a perfect stop could be made in 161 feet. What if James decides to try and turn to his right
to avoid the crash, while applying his brakes. Like I said This is a very dangerous maneuver. If he is at 100% braking power,
and he attempts to turn the bike, he will exceed the 100% traction threshold
point, and cause his bike to skid. Once a skid starts, the coefficient of friction
between the road and his bike changes. Before with rubber on asphalt
the friction was .7 Now that his bike is on its
side, the bike is mostly metal and plastic which has much
less friction with the road. This means that he won’t be able to stop
in less than 161 feet, but due to his skid, he will need more distance to stop. In a controlled skid he would
stop in about 193 feet. So how can he brake and turn at the same time? He can only turn the bike if he is using
less than 100% of his braking power. Whatever percentage he reduces his braking
power, he can use to apply to turning power. If he reduces his braking to 75%, then in a perfect
world he could use the other 25% to turn the bike. If we assume he is braking
at only 75% of the full braking power, he will stop
the bike in 201.25 feet. And if he uses the other 25% of turning
power which can only come in another one second after James is able to:
Identify, Predict, Decide, and Execute. So one second after the perception,
he begins to apply his brakes, and starts to LEAN
the bike to start to turn. And it will take about One more second
to get the bike to start to turn. The total amount of time from
the Perception of the car of the bike to begin to turn is 2.5 seconds. With 75% braking power and 25% turning,
he will be able to stop in approximately 200 feet, and he will have turned
his bike to the right by 5 feet. If James is traveling at 50 miles per
hour he is covering 73 feet per second. So if we had him make a perfect 100% stop, it
would take 93 feet to come to a complete stop. Now let’s add 1.75 seconds for
perception time or 128 feet to give James time to perceive the danger
then he could apply his brakes. He could stop in 220 feet. If we factor in a reduction of braking power to 75%
and turning maneuver beginning at 1.5 seconds, then he will stop in 275 feet, and turn the bike to
the right by 5 feet again upon reaching the stop. Both of these examples would be
virtually impossible for a rider to do. These examples are assuming 100%
effective braking and turning. This is not possible. However, if the bike had anti lock brakes, then these maneuvers are going to
be closer to 100% effectiveness. But most bikes do not have
anti lock braking systems. To summarize this example, there is
Reaction Distance, which is the distance the bike travels for the driver to
identify and react to the danger. Then there is Braking distance, which
is the distance traveled from the time the brakes are first applied to the
time the bike comes to a complete stop. Then there is Total Stopping Distance which is
the total distance it takes to stop the bike from the moment the driver sees a problem
to the time the bike is completely stopped. Reaction Distance + Braking Distance
=Stopping Distance. As a trial lawyer handling
a motorcycle crash case the issue comes up whether the biker
should have turned or gone straight? I will ask the Defense Expert: “would you
rather ride into the side of the car and eat the roof rail and the B pillar, or would
you rather go over the hood of the car? Their answer is almost always that it is safer to hit the hood of the car
rather than the roof rail. In this case, James made an Active Decision to go over
the hood of the car in this scenario, and it probably saved his life. I hope you have found this video informative and I hope that you are more
aware as you enjoy your bike, so you can drive safely, and be prepared for
that car that’s about to come into your lane. And please practice your emergency braking
until it becomes automatic for you.

25 comments on “A Real Life Example of a Motorcycle reaction Accident Reconstruction

  1. I had exactly that scenario in a crash a month ago at the time I decided to turn right and brake, my bike doesn't have abs so I skidded my rear tire while I maneuvered I hit the hornet and a couple seconds later the driver realized his mistake he proceeded to slow down and initiated a turn to the left at the time it was already to late and I impacted the right side of his vehicle, fortunately I didn't suffer major damage due to my rolling reaction upon hitting the road, I was wearing a backpack full with books and a water bottle that broke upon impact with the ground, after hitting the right side of the car I rolled in the ground and I also hit my knees a bit. Everything could have been avoided if I would have been going slower or the car driver had been more aware of his surrounding's, lesson learned always slow down on any type of intersection. Thanks for the video it provided an excellent illustration combined with a detailed explanation of all factors that I learned upon my crash experience. I'll watch more of your videos to avoid making a mistake in the future thanks!

  2. Speed and direction , are you telling the my story by any chance? This happened to me and I reduced speed and went far right(more like turned right quick then hard brakes) but keeping in mind he might completely block far right so I gona start a full out emergency brake , only if he blocked the right totally. going back left wasn't available due to time.

  3. I crashed into a car pulling out into the second lane, from the right. I decided not to turn because I didn't know what was behind me. I applied braking, most probably skidding with the back tire but not the front, and hit the front wheel of the vehicle. It may have been a little slower than 40, because I wasn't thrown. The bike bounced away and I jumped.

    I would have benefited from reducing speed and moving to the other side of my lane to improve braking distance and give myself longer to react.

    In the situation in this video, I would see the potential threat and immediately begin to slow to avoid the imagined impact point, until I know I can pass before the vehicle moves AND/OR stop if it crosses the lane. I would also check my mirror, indicate and cross to the right lane, making myself more visible to the threat with flashing lights and lateral movement, which is easier to spot, especially at night, and also warns other motorists of a potential hazard. Hazard lights might even be appropriate. This is especially true in places where people violating your right of way is common.

  4. James should have assumed a car was being blocked by the green car, and this blocked car might pull up in front of him, therefore slowing down and being ready to break before the whole thing happened. I do it even while driving cos I assume the worst of other drivers.

  5. Please make more of these! There aren't enough studies, examples, and science in motorcycling safety. Too many assumptions and guesses.

  6. So no way to avoid it. Only choice is how badly do you want to get hurt. Got it, glad I decided to watch this 1 week before buying my first bike…

  7. Thank you so much for this. I lost a friend a month ago and I’m a need-to-know-how-things-work type. I had a lot a questions and you answered a lot of them. I live in Tampa too and have a few more questions, I’m sure you even heard about my friend’s accident. Please let me know if I can send you a message.

  8. Basically your fucked. What a rider should do is see the threat and act accordingly, i.e reduce speed way before the intersection when a car is spotted waiting. Best rule; scan all upcoming intersections – see a car waiting – slow down, change lane to the furthest away if applicable, cover the break with your hand to slow down reaction time and be prepared to stop at any moment. After drink riding the number 1 cause for motorcycle fatalities is intersections.

    Tip 2: When waiting at a red light at an intersection do not speed off as soon as it turns green because this is when people get T boned by people who skipped the red light at the last second, wait a little bit before bolting off.

  9. Just to add ABS stops you from locking up and falling off, it does not improve braking if anything it makes it worse. If you hit the brake hard, its job is to stop locking, it does this by unlocking your tyres (releasing the brake), and then applying the brake, this actually increases stopping distances but stops the rider from locking up and falling off. Most effective way to stop is braking without the use of abs being enabled, i.e. gradual increase on the front brake till you reach 70% squeeze then add 30% to the rear brake – keeping the bike straight bars straight. Obviously when a car is about to smash you and you are panicking this delicate routine is very difficult to achieve and that is why I practice it time and time again in empty car parks, so that it is in my muscle memory and becomes second nature.

  10. Excellent video,where each & every details u mentioned, only the riders face & understand. Gra8 work bro.

  11. Excellent video, as an insurance adjuster I investigate these types of accidents daily. It is nice to see some of the science behind a crash. Very informative. This type of information really should be presented to some of my coworkers in the business.

  12. As soon as James saw that red car lining up for theft turn he should have moved into the right lane if possible which would have allowed the car to see him sooner. James should have also checked and even reduced his speed when first seeing that red car.

  13. This crash looks so similar to mine that it's weird: watch?v=4KgYer96k20 Mind you, the turn that van took was illegal. But according to this video I did everything I was supposed to in the 1.2sec I had between seeing the Van and hitting it.

  14. Thanks got it, Get ABS, Squease to save my life and aim for the right and before approaching areas where people can join make sure no one is to the right of me

  15. They were so many mistakes from the red car and from James..First the red car went to far before turning left . Second, from James view he could have spotted the red car and move to his right into the next lane or he could have slowed down to be safe til the red car spotted him…..All this could have been avoided…always imagine the worst in relation to other drivers…you are the only good driver on the road and others are bad drivers.

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