I said from the beginning the semi ran the stop sign. I have driven that exact highway over and over again. The bus driver has driven this hockey team everywhere. The bus driver was very experienced. The semi driver only had 2 weeks of driving and had no experience whatsoever.

I hope you will update us as the upcoming trial proceeds. I trust your analysis, and when we get more information, we'll be able to nail this down with your help. Thank you again.

Thanks for this. Clear and convincing, and I think analyses like these help keep the investigators honest.

A good analysis, It is fairly typical for people to travel at around 110 Km/h on both of those roads when conditions are good, as they were that day. I was there a few days ago and there happened to be a semi stopped at the intersection on 335 I could see the whole tractor and probably more than 1/2 of his trailer. It would be interesting to see where they would first be visible to each other past the trees when traveling at highway speed. The skid marks in the west lane may not indicate where the impact happened but where the tires of the truck were pushed sideways from the impact further back on the rig. If it is from the bus impact at that point then the bus driver may have reacted to the sudden appearance of the truck in front of him by steering in the same direction as the truck was going. Steering to the east might have been a better option to avoid a collision, but with the truck being a B-train it likely wouldn't have helped much.

This has been on my mind forever. I follow your calculations. Thanks so much.

The road that the semi truck was traveling on actually has a speed limit of 60 km/hr before approaching the stop sign. A truck driver posted a video of him driving down the same road less than a week after the accident. Signage is very visible...

I am a high school student who lives about an hour out of Humboldt. I have used Charlie's charters before, as well as PA northern, the two big charter companies in the area. For football and hockey. No way in HELL are they going to drive over 100km/h. The drivers are very very cautious and care about their cargo a lot.

I think you did a fine job of showing us the what IF's and maybees in an unbiased manner.

This is really well done. Great analysis

Thank you sir for doing this! I hope it will give some answers to the families and friends of the victims. It is inexcusable that after all this time, the RCMP and the Canadian media have remained completely silent on what happened, and have totally protected the identity of the truck driver. This information should have been out a long time ago. We have known since Day 1 what happened, as one of the Humboldt Bronco players has testified he saw the truck and heard the driver yell "Whoa!" just before impact. In addition, a father of one of the victims following the bus who came upon the scene asked an RCMP what happened and was told "The truck blew through the stop sign". No charges have been laid, as the RCMP say it will "take a long time" to figure out what happened. Nonsense! And the Canadian media are just not reporting the facts as you have done. Why we have to put up with this, is beyond my understanding.

You can't argue with physics. I've had the same theory since seeing the photos of the aftermath, that the truck NEVER stopped.

ok people I love the inspection now check the weight , that tractor trailer combo is called a B train (40,000 lbs ) it can carry over a 100,000 lbs so it is three times heavier then a bus . That bus did not cross the 335 at all , it hit a brick wall of peat moss and an inexperienced driver in a tractor trailer . the driver clearly ran the stop sign because that's how they drive .

THE BUS DOESN'T HAVE TO STOP, ITS ON THE HIGHWAY. THE TRUCK DIDN'T DO A FULL STOP OR WAS ON HIS PHONE.

Another split second and they would of missed each other and the truck driver would of kept going not even knowing he blew a stop sign. Only a matter of time before that trucker would kill someone else.

Seems like there is something wrong with this picture like/ I have learned Lack of answers in bus crash investigation fuels anger (CBC comments disabled!)........... I have been involved in the trucking industry for close to 40 years driving coast to coast and even operating the very same rig and even a very similar load involved in this accident. I was also born and raised in Saskatchewan and lived here most of my life and I do know these roads very well too!!! I believe this accident is being over investigated. Yah where are the charges? Careless driving causing death. 10 years in jail !!! Or even dangerous driving !!! Why do I have the feeling this is going political !!!! Its very obvious the truck driver drove thru the stop sign like it wasn't even there!!! I also believe the owner of the company should be charged with something too.... Letting a rookie driver operate a rig like that in he first place...

The bus's front was demolished while the pup trailer was hit directly. The bus was doing at least 70MPH and the truck must not have stopped at all. The truck driver is unskilled and caused the accident, of this there can be little doubt! Tragic

Excellent analysis. Know the area, the roads, the vehicles, possible conditions. Given this and the experience of the Bus Driver(RIP) then the unknown remains the semi units operator's condition and skill level. This is still in the hands of the RCMP Traffic Investigators as there are other issues that must be sorted fully before they release their findings.... and it has a lot to do with the implications on the other driver, the industry and the legislators. Once released there will be serious lawsuits and a lot of anger... don't rush into this please. A lot more pain can still come forward especially for those who lost loved one's. This piece of analysis is very important to all as it helps to prepare for the inevitable. Thank you

The department of highways in Saskatchewan is guilty of criminal negligence. For one, the sight lines approaching this intersection were inadequate. The property owner should have been forced to cut those trees. Second, if this intersection was known to be dangerous, which it was, as 5 people were killed at this intersection in the past, something was required to make it safer, such as a four way stop. The DOHS is just as culpable as the truck driver who failed to stop. Someone at the DOHS needs to be held accountable, and go to prison!

This is Not an accident it is called a motor vehicle collision....the reason the truck had a 60kmh speed sign is to in able for a vehicle to have distance and be slow enough to facilitate a stop....the driver needs to be charged with 16 counts of vechical manslughter and the owner of the company should be charged as well under OHS legisation for allowing that driver behind the wheel and may we can start to repair the trucking industry

Thank you for the discussion. I appreciate the effort to put out information for people to ponder while they wait for the RCMP to finish their investigation. Reaction time is important in life! When driving, time is distance. For everyone else, things to remember are that these numbers are based on some assumptions (as the narrator goes through in detail.) Yes, there is a delay. Initial reports had that the driver of the truck did cooperate with the RCMP, and was released. Now the RCMP Crash Investigators, Analysts, and Reconstructionists, are doing their thing. The physics will tell a tale, and will be based on the actual measurements. The interviews with witnesses, the surviving driver, the companies involved, maintenance records for both vehicles, data recorders on the vehicles have been sent away for analysis, weather/sun reports, and a lot more will be evaluated and worked on, then double checked, etc. This video shows a small (and important) part of the discussion. Telling what happened is part of the whole. The why sometimes takes a bit longer. Thanks again for showing people part of the story, I hope some understand why this takes so long.

I don't understand why this truck driver hasn't been charged. He blew through a stop sign killed 16 people and injured 13 others and nothing has happened. And why do the RCMP have a gag order on all families and survivors and anyone that witnessed the accident? And why is it taking so long to investigate, and is the driver still in Canada

Sad but true. First yr engineering problem. Reaction time is o.5 to 0.7 sec, at the best of times.

Thank you very much. Well done.

does the extreme length of the truck make any difference? it is double the size of a regular truck. would take forever to move from a complete stop

this is very well done

Wow.....great video. Thx.

Good physics refresher. A bit of a stretch from my usual rotational dynamics. Thanks! I suspect - human behaviour being what it can be - is that the trees played a bit different role than simply possibly blocking sightline from a stop sign. The truck driver likely did a quick scan to the south just before he got to the triangle of trees and saw no traffic coming. He looked way south, before the farmyard obstructed his view. I'll speculate that the truck driver simply didn't see the bus because it was already hidden by the farmyard. They moved along their trajectories. The bus going a bit slower. The truck driver didn't think he had to stop because he saw no traffic coming from the south as he approached the farmyard, far back from the intersection. A fatal calculation of a "short cut" if there ever was one. So sad. Rules & signs are everywhere. For good reason. They protect us from bad luck and deadly chaos.

Thank you for your scientifc analyses, I have always stated that the truck driver never stopped at the stop sign. He has probably traveled this route many time not occuring any traffic. So, he probably decided to blast through the stop sign to meet his deadline.

Using your factors for the angles of reaction, I submit that both vehicles were traveling close to the limit with the truck ignoring the stop sign. Your equation would put the truck on a mass of 54,687.5 kgs, which Is believable for a loaded B-train. Your deminstration adds proof of what any in the logistics industry assumed as soon as overhead photos were shown.

Was wondering if google earth was the program that did the measurements or if you just uploaded the image to another program. Not questioning your video was very informative and quite usefull if I knew how your did it. I own an acreage and would like to do measurements like you did. Thanks.

Sad to say that you are right!!! As soon as I saw the pictures of the " INCIDENT", I knew the trucker was at fault!! I have been working in the trucking industry as a mechanic for .... 20 some years and the quality of drivers dropping at an alarming rate!! So bad that I cannot in good conscience ...... I had to quite!!!! The driver is, sad to say ........It's the kids and the driver that didn't have a chance!!!!!!!!

The truck was hauling a super b trailer, meaning the weight was 63,500 kg and using the calculation, the speed of said truck was 87.5 km/h.

When I worked in the claims department of a major insurance co., I investigated thousands of MVA's. Just look at the remains of the accident, and where the vehicles finally came to rest. FACTS - there is no damage to the front of the truck. The front of the bus is completely destroyed. The trailer (of the tractor-trailer) was struck on the left side. ERGO, the bus t-boned the trailer - because the truck and trailer(s) pulled in front of it suddenly, which meant the truck,et al ran thru the stop sign at full speed. AND the bus was traveling very near the intersection, at full speed. Momentum carried both vehicles thru the intersection to the left, giving more evidence that the truck blew thru the intersection/stop sign/flashing red light at full speed. Now, want a prediction, as to what happens next, based on 15+ years of experience? The owner of the "trucking company", and that punk/dangerous/inexperienced driver(both of whom are probably illegal aliens - that's why they are both "operating" under Canada's relatively lax laws) will simply disappear. Their insurance coverage is probably very sketchy - if they even have any, which will leave who-knows-what insurance companies to foot the bill, which they will probably weasel out of, leaving the victims, the school, the owner(s) of the bus, etc. etc. holding the bag !! (I've seen similar scenes hundreds of times). The owner of that BS "trucking company", and that so-called driver will hightail it back to "dirtcookie", together with all their "families", and, when things "cool off" they will return, probably using aliases, and start some other potential disaster. (seen it all before) I would be very surprised if there was any other final outcome.

Have we had a reported speed on the bus from a black box? I know some buses have governors on them, so did this bus have one?

When determining the mass of the semi, did you consider the weight of the peat moss? I'm just wondering if that would affect the point of impact, or the speed of travel of either vehicle?

Excellent analysis , and what I’ve said since the beginning. I have 40 years experience of truck driving and mostly super b since 1988. The truck had eight axles, and combined have an empty weight of 40-42, 000 lbs. the peat moss was likely 80 thousand lbs. your bus weight is probably correct. I travel at 100kph always. Buses always pass me. So 110-120 before he hit the brakes is likely. Those new truck drivers always go over the limit. So again 110-120 kph is likely. Good work!

You have shown conclusively that the truck driver did not stop. I was just wondering what the speed of the truck would be if you assume its mass were bigger, say 60000 kg. Wouldn’t it mean that the speed would have been 20% lower? Still not even close to a full stop, and very little time for the bus driver to respond.

thanks for the analysis. It shows what most of us thought. Now when will the police issue their findings?

It is possible to dispense with all conjecture because the truck has a black box that records the vehicle's speed, engine rpm, gear selection, brake applications, and the pressure and duration of all brake applications; for the past YEAR!!!

Amazing results. Sob blew the stop sign for sure. Driving for to weeks. Put him in jail. 🤬😡

A reasonable weight for a loaded semi would be about 62500 this would mean the truck was traveling at 87km. Just saying. Obviously the truck didn't stop.

Am I not correct in understanding that tractor trailers and busses be governed at 105 km/h by law?

Good video. The truck was a fully loaded 8 axle unit. And with peat moss was undoubtedly very close to gross weight of 62,500 kg.

The numbers I used for truck weight were 62500kg. Legal max on the route he was taking. He was going 87kmh. And bus going roughly 100

IF the truck had STOPPED at STOP sign , this whole accident would not have happened , pretty simple . doesn't matter IF bus was speeding.

It is not has fast the bus was going. But how FAST the truck was going when he blew the stop sign. Also it takes quite a while for the whole truck to clear the intersection.

Any way you look at it.The truck did not stop at the stop sign.

I enjoyed your explanation. Question. When 'Reaction Time' is quoted, does that include the time for the Bus driver to hit the brakes as well as stopping distance required? Does the fact that the bus was spun around about 120° after the impact enter into the equation? Weights and speeds do not change. The Speed Limit for the Truck is 60kph 35 mph as the Stop Sign was approached. How long would it have taken the Truck to clear the intersection from the Stop sign at 60 kph? A couple times Bus/Truck was interchanged in the audio but it is and always has been clear to me and others that the truck ran the sign at considerable speed. Great presentation. I needed you beside me in Math classes.

Instead of assuming the bus was doing 100 at the time of the accident, why not assume that he hit the break at the same time the witness said the driver acknowledged the truck in the intersection'?? Your final number would be smaller. A half empty bus would also weigh less, and a set of b trains would likely weigh more. Sure lots of variables, that's for sure.

The semi driver should be charged for all 16 deaths.

GVW Gross Vehicle Weight of a Super B is 63 500 Kg (139,700 Lbs), the weight is determined by adding the following steer axle 5500 Kg drive axle group 17000 bridge axle group 20000 Kg trailing trailer axle group 17000.There is an error in the data set. Because of this error in the data set the correlated information is wrong.

However, go back a few hundred metres and look to the right & you can see the truck coming long before the intersection & should have been aware of it long before the intersection as the fields are flat .. Neither driver was looking OR seeing " the big picture " as we all should when operating a motor vehicle.

Let the kids Rest In Peace

Truck driver blew threw the stop.

Just wondering why no compensation was made for the fact that the semi was loaded at the time?

Life-long American trucker I am, (40&years) totally unfamiliar with Canadian roads as I have never driven there, but as soon as I saw the original news article, I knew it was the truckdriver's fault, (it was international news) even before I saw the intersection involved, and the stop sign. I am suspicious as to why the RCMP did not wrap up the investigation within 1-3 weeks. Of course by now, I have seen everything our glorious free information internet has discoursed since then, which is an awful lot more damning for the truckdriver, if you feel like calling him, which I DO NOT! Had I made his mistake, I would have commited seppuku, to show family, friends of those killed how sorry I was. Yes, I have 3 kids and 8 grandkids, but they would understand, and so would the victim's family, RCMP, quit dragging your feet!

Truck going more than the speed limit and failed to stop...simple.

Truck crossed in path of bus making truck 100% at fault.. no analysis required

Did the driver take a drug test and did they check his phone to see if he was on the phone or texting?

Note from pictures of the crash, the truck was an 8 axle/62,500 kg. Also, these boys were about 180-200 lbs (data from sjhl.hockeytech.com) plus gear would be about 50 lbs. This reduces the truck speed to 95k/h. Still, truck driver was at high speed through the stop. It would be interesting to calculate the sun angle and corroborate if the truck driver was blinded by the sun and did not see the stop sign or flashing red light.

You can't beat Physics.

At 18:52 you make an error in your assumptions. I doubt this will affect the final conclusion, but it may affect some of your specific calculations. The GVW (gross vehicle weight) on a bus of that style is typically 20,000 kg. (44,000#). GVW is the MAXIMUM the vehicle is allowed to weigh in any condition. The TW ( tare weight) is that of the empty unit. This style of bus typically has a passenger capacity of 55, so it was just a little over 1/2 full. Now, as it was a sports team, it would be reasonable to assume the passengers would have had extra equipment, adding to the overall total weight. Thus, it would be reasonable to expect that the bus would have weighed around 80% to 85% of its allowable GVW putting the total weight at around 16,000 - 17,000 kg. The B-Train was licensed for 63,500kg (You can see this on the label of the truck in the CTV wrecking yard video.) The TW of this unit, truck AND trailer combined is usually about 17,000 kg. The load was comprised of 18kg (40#) bales of peat moss. There are 48 bales per pallet. The front deck has is 32' long and the rear deck of a b-train is 28'. (This unit actually appears to be shorter in the pics - may only have been a 20 footer.) This gives a maximum capacity of 30 pallets. 16 on the front trailer and 14 on the tail. 30 pallets, weighing 1000 kg each, plus the TW of the unit, puts us closer to 47,000 kg mass for the rig. That would put him at about 75% of axle capacity. Despite his weight, he would have still had a considerable amount of "get up and go."

truck ran the stop sign --- seems the only possible reason for this.

Were there rumble strips at that stop sign?

The bus was in the north bound lane, not the south bound lane.

Interesting analysis. Its obvious the truck ran the stop sign but the question is why did it fail run the stop sign. It would be interesting to see what your calculations would come up if you gave the truck its Max GVW of 62,500kg

The bus hit the truck, hince why the entire the front of the bus is gone, and the front of the truck remains untouched

The fact that the the bus was traveling north and the point of impact is in the left lane, in the first trailer, kinda paints a general picture.

You can eliminate the first 14 to 15 minutes of this video to get to the gist of your collision hypothesis. Most of this video is a waste of viewer time. The bus collided with the first of the two trailers after the transport blew the stop sign at a good clip. The cab cleared the bus coach but not the trailers. The combined impact was enough to send the transport onto its side, tear almost half the bus' front section off and spin around the remainder. Both vehicles would be traveling 110-120kph. There are no discernible skid marks that either vehicle attempted emergency braking.

You forgot to include the peat moss load weight onto the truck’s GVWR.... So 20,000kg of load + 50,000 GVWR of truck. If bus was doing 100km/hr with your formula the truck was doing 80km/hr through the intersection.

Too bad none of this will bring those lives back.

You didn't calculate the load on the tailers. A critical error that changes everything.

Nice start to an analysis; however, I feel it is incomplete. Given the mess of peat, it is likely that the Super B was operating at it's maximum GVWR/legal weight, which would have been 63,500Kg. Conversely, the bus was carrying 29 passengers. Given that hockey players are generally larger than average, and accounting for gear and luggage, you are lokng at around 110-120kg per person on top that f the bus' empty curb weight. This would be round about 19,250kg. Using the distances you (accurately, IMO) calculated, the velocity of the truck would have been 80% the speed of the bus at the point of impact, meaning had the bus been going 100kph, the truck would have been going 80kph. 20kph over the limit, but not as drastic as you surmise. It may be more accurate to estimate the speeds using the distance traveled after the collision. Data on average collision acceleration rates should be available. Plugging in the distance travelled along the x and y axis, over that (those) acceleration rates, should yield the initial velocity/range of reasonably likely velocities of the combined mass. From there, determining individual velocity of each vehicle should be a matter of applying the momentum to the specific mass of the vehicle travelling along that vector. With that, it should be possible to better determine the actual range of reaction times available. Basically your process, but backwards.

your vector angles are wrong, look at he scratchmarks at the intersection there is a near 45 degree angle. at the point of impact the bus weighed 16000Kg and the truck weighed 63000kg. due to the extreme violence of the collision there is a 3rd vector we must consider besides North and West and that is straight up... the resting points of the bales confirm this. the twisted B-train we can estimate at 20000Kg at its final resting point after being separated from the load, also the 2 hinges (5th wheels) make this very difficult to calculate. After months of studying this my best estimate is that the semi was doing 40Km/h and the bus was doing 90 Km/ at the point of impact.

I don’t think he over analyzed it at all. This is exactly what the police will do only they may have the availability of knowing the speeds involved. They will recreate the accident in an animation. I think this was well done. My opinion.

4 way flashing red light!

If we had cameras on the bus and truck we wouldn't be going through all this lengthy investigation. We need governments to make it mandatory for trucks, buses and cars for that matter, to have cameras. For $100, they are worth it!

You didn't factor in the weight of the semi's load

Great video, as for the truck driver, I don’t mean to sound judgmental but I think he was possibly texting. That can be the only explanation. I used to unload trailers at a grocery store, while we were unloading I would see the truck drivers with their faces in their phones constantly. That’s why I figure he was texting.

Please make the same analysis for the Manitoba Hwy 1 / Hwy 5 crash. The bus appears to be at fault and with analysis like this one, we can be certain that it was. Thanks for considering.

Poor truck driver he prolly feels so bad😢

The truck would have been 62500

I notice a few times a mix up at the tongue truck/bus not that you weren't doing a fantastic job.

From all my years in the towing business and see many truck accidents and seeing the twisted steel from the trailers .also hearing the players comments about standing up to see what was happening .the bus was grossly speeding! Also the truck had to of had gown trough the stop at a fair speed. The steel of the trailers would not been so twisted if the bus was not speeding. Thanks for the physics

This guy's calculations are completely screwed! Notice how he has to "Fudge" his numbers, not once, twice, three, four times to get a Semi speed closer to 100+ KMs (wasn't one speed 169 K/hr??) He has the bus over weight! When you see posted weights, those are the MAXIMUM Weights (use listed weights by a manufacturer like MCI - NOT GREYHOUND), therefore, the maximum weight (GVWR) for a bus, carrying 55 passengers is 48,000 LBS (not KG). The bus was only 63% full so the weight was closer to 30,000 lbs. The final position of the bus, distance from the intersection, he is using, is WRONG! (That is the position of the Semi! Look at photos from above provided by the RCMP). There were NO ROAD/WEIGHT RESTRICTIONS on Hwy's SK 35 or SK 335. The MAXIMUM Weight (GVWR) for the Semi (as placarded on the driver's door, again check the photo from the compound the Rig was held at) is 63,500 KG (not the 50,000 KG in his ASSumption). BTW 63,500 KG is 139,993.54 LBS which is 4.66 times heavier than the bus, assuming maximum weights, again which the bus WAS NOT! That's why the bus ended up within one bus length (45'6") from the point of impact. (Tire marks of the bus moving Westward at impact vs North - Direction of Travel). The FACTS as REPORTED SO FAR ARE, the Semi Driver admitted to NOT SEEING the STOP SIGN (Statement released by the RCMP), therefore, he did not stop (does not matter how fast he was going!) The BUS DID HIT (T-Bone) the Semi which was already in the intersection. Now ask any COP, "Who is at fault in an intersection, when one vehicle hits (T-Bones) another? (Known as "Entering an intersection while not safe to do so"). Now, the deceased bus driver, (Sucks to say it), can't defend himself. NO CHARGES HAVE BEEN LAID! There will be charge(s) laid, but not the one's people expect. The final report by the RCMP into this accident is at least 1 year away (the Aircraft accident the killed Jim Prentice (Oct 2016) was just released last week (a year and a half after the accident). The Province of Saskatchewan will carry a burden of responsibility for not having RUMBLE STRIPS at that very intersection that killed a family of six in 1996! For now, this is a horrible accident, without any race of the those involved, skill level/experience or training. Just saying.

Bye trees

I need a new calculator

on the wheel of every semi is a speed recorder = case solved.

Just wanted to say that Canadian trucks have a mandatory speed limiter on their trucks. It's 105 km. Probably you're magic number. Just saying

109 km? That speed and weight would have sent him way down the road like when a train hits a car. I believe the truck was doing between 10 and 20 km. Either he was just pulling from the stop or couldn't stop in time.

OK i agree but you put the weight of people on the bus but not the weight of semi load don't get me wrong i beleave 100% semi was at fault speeding but put the weight on semis load and lets see the results

Truck weight of 70,000 kg

Why aren't the RCMP doing these calculations.

Stop sign too low maybe red light wasn't flashing or sun got in the way of vision?

my condolences to the victims who have passed. The families that have been affected.@agathokakologue i appreciate the breakdown. in my observation it was definately a rolling stop, however how fast was the bus driver driving?

So what's the truck driver's story? Whatever he said hopefully it was the truth, because this was the equivalent of Marshall's football team! Sad beyond words😣

Although I was positive the trucker had run through the stop sign at about 120km/hr before I saw this video because most East Indian or Punjabi truck drivers of which I am one would be going about 20 km/hr over the limit on this road. I would like to thankyou for making it clear to anyone else who had any doubts with your in depth use of physics. You did a great job and I can't understand why the police have not been able to complete their investigation as of yet. Physics doesn't lie.

Thanks. I am sure the truck driver can barely live with himself after this.

Was the bus driver out of hours? What does the truck and bus’ black box show. They both have them. Either way the Bus driver lost control of his vehicle and the truck driver can prove he stopped.

Interesting analysis but is extremely simplistic physics. Example it is treated as an elastic collision when in fact it would be an inelastic coalition. There are many other errors., physics does not tell what is claimed. This would never stand up in a court and should not be used to make assumption of guilt.