A different type of thread for Crash Analysis: Lane Splitting

[Outta Control]

I do find it interesting as to why the rider stood the bike up on frame 1:19 but I do agree he should have had better SIPDE judgement.

 

[ctwo]

Can't top Dan's post. I notice a few things with traffic and that is often after on ramps/mergers like this and when traffic backs up, folks are shifting around and I expect many will have their left lane tracking beam on.

I've been offered this pass several times and I especially do not like it because of this type of risk and that there could debris in the shoulder than puts the driver back into you.

Last, I do not think this had anything to do with motorcycle visibility. Even the truck was in a more visible location and was not able to stop before passing the left lane grabber. Someone asked if the van blocking the view could have contributed and sure, I have seen this where people cannot see and just go on blind faith.

 

[EastBayDave]

Unfortunately, I don't think that odds are in favor of most people being able to avoid a collision under these circumstances. And unfortunately, you can see riders all the time who think they too can avoid splitting splats, despite outrageous deltas.

It appears that the video truck might not have been able to stop in time to avoid a collision with the lane changing auto, either. Thus the speeds were definitely exceeding any reasonable "safe zone". I have stated numerous times that I don't trust these drivers and never pass them in the same lane.

I use them for blockers! :thumbup

Unnecessary lane sharing at excessive speed seems like the simple reasons for the collision. Thus, don't split at high speeds and ridiculous deltas, even if you are the second coming of King Kenny Roberts.

agreed!

Seems some still don't hear us? :thumbup

Excellent analysis.
Stopped/barely moving cars next to a line moving at 50+ sets off massive alarms in my head when I'm splitting. I'll usually just stick to the left and sit a generous distance behind a cage and wait for the other lane to start moving again.

Ebd= Again, I do that when splitting, use THEM as a "blocker"to save YOU from a collision!

Sometimes when I've been a bit impatient, I've broken that rule and sometimes I've had a near miss because of it. Impatience kills.

My commute from Concord to the city can be anywhere from 35 minutes with zero traffic to 50 minutes with heavy traffic. I might be able to shave off 5 minutes if I ride like an absolute lunatic ... but it's just not worth it.

yep; some need to wake up before their dead

Wow DD that was well done research and analysis. :applause

:cool :thumbup

I still believe even if the biker swerved and missed a collision, the recording vehicle would have slammed into the cutlass anyway. He/she simultaneously changed lanes and turn on the blinker at the same time.

Normal; morons just assume you'll see them, & it -appears- legal. Duh.

Can't top Dan's post. :thumbup:thumbup:thumbup:cool
I notice a few things with traffic and that is often after on ramps/mergers like this and when traffic backs up, folks are shifting around and I expect many will have their left lane tracking beam on.

I've been offered this pass several times and I especially do not like it because of this type of risk and that there could debris in the shoulder than puts the driver back into you.

Last, I do not think this had anything to do with motorcycle visibility. Even the truck was in a more visible location and was not able to stop before passing the left lane grabber. Someone asked if the van blocking the view could have contributed and sure, I have seen this where people cannot see and just go on blind faith.

Great stuff everyone; those who don't care, prepare to be an organ donor:
get your affairs/wills in order... Blunt, yeah =but this is where you might end up if you keep up this crap on the too crowded lanes around the bay... Wake up if you have read this far....:afm199

 

[Enchanter]

Great advice from another thread:

When it really goes wrong, your godlike braking skills won't prevent the crash, and your protective gear won't prevent death or serious injury. You need to understand potentially dangerous situations and take action before the danger is revealed.

 

[motomania2007]

That is a lot of delta. Not sure he could have swerved but it did appear that he target fixated on the car he hit and there was space to the left. Not sure if it was possible to avoid the collision given the speed and space.

What is avoidable is placing himself in the situation to begin with.

His poor judgment and/or bad habits placed him in that very risky situation, as described in more detail in previous posts.

A pretty harsh reality check!

Hope the rider was not hurt too badly.

Like I explain to students in all my classes:

What we teach in this class is judgement and strategy. I give you some tools of good judgement and strategy and teach you how to use them. Whether or not you actually USE good judgment and strategy, is 100% up to you, the individual rider.

 

[Honey Badger]

DD's post pretty much states my thoughts only far better with more information than I could put together.

Those situations (one lane moving significantly faster than the one next to it) are the highest risk IMO. Cars are stupid about other cars in these situations, none the less taking the time to notice a bike.

My preferred method in these situations is to put a nice visual gap between me and the car in front of me and stick to the left side of my lane. This gives me a buffer to swerve if I need to, and enough time to react if I see a car darting in behind the vehicle I'm behind. Already being on the left means I'm that much closer to a full-on shoulder jump if I need to.

 

[philipviana]

I would never split like that when the speed difference between the #1 and #2 lanes is so stark. HOV lane is moving 20-30 mph faster than the #2... why did he have to split? The road is wide open ahead of the truck, the rider should have known that drivers in the #2 would want to move over into it.

The offending driver made a bad lane change considering the truck in the #1 would have had to have slowed down abruptly, but it's worse judgement on the part of the rider IMO.

EDIT: more like a 50 mph delta, jesus!

 

[NudeMischief]

The crash happened here (Google maps link) on southbound I-880. Via Climber's CAD archive, the rider suffered only minor injuries.

By my estimate [1], the camera vehicle was doing 65mph, the motorcycle 90, and traffic in the #2 maybe 5-10 near the crash.

Once the rider passed the camera vehicle and the Pontiac came into view, he had no chance of preventing a crash either by braking [2] or swerving [3]. So his last chance to avoid the crash came before he split past at 90.

What should he have done?

1. Know how lane-splitting crashes occur. Most commonly they happen when a car changes lanes across the corridor. All lane-splitters should commit this to memory and follow it as a fundamental principle.
   
   
2. His delta to lane #2 was at least 75mph. Insane. If it takes 2 seconds for a car to complete a lane change, the motorcycle was 200ft behind when the driver began his maneuver. The purpose of keeping speed differential down is to give drivers a reasonable chance to see the motorcycle and to give the rider a reasonable chance to avoid impact due to an incursion. It follows that the the delta applies to the slower of the two lanes.
   
   
3. He shouldn't have been splitting AT ALL between a 65mph lane and a 5mph lane because the delta will necessarily be excessive.
   
   
4. In a free-flowing lane next to a stop-and-go lane, he should have been occupying his own space, not splitting, positioned near the left edge of his lane. The full 12ft lane width of space cushion would give him extra time to overtake the intruding vehicle. As it was, with no space cushion, he was in the worst possible position to deal with an incursion from the right.

---------------------------------------------------
[1] This note will describe my speed estimates. If I got it wrong, I welcome a correction. To estimate speed, I measured distances in Google Earth and time with my Timex stopwatch. Camera vehicle speed calculated between HOV diamonds here (37.410336, -121.911325) and here (37.407641, -121.910490), average of 3 timings. Motorcycle speed calculated between lane line segments here (37.407570, -121.910480) and here (37.407177, -121.910400), also average of 3, but this estimate is shakier. Lane #2 estimate is basically a WAG of time to traverse a 14ft lane-line segment.

[2] When the motorcycle pulled even with the front of the camera vehicle, the eventual point of impact was 180ft ahead. From 90mph with ZERO reaction time, that would take an average of 1.5g deceleration. The best published motorcycle braking performance is about 1.0g.

[3] At 90mph, it takes about 1.4 seconds to cover the 180ft between the front of the camera vehicle and the eventual impact point. To swerve a full lane width (12ft) in that time would require an average lateral acceleration of 12ft/sec^2 with ZERO reaction time. I'm not certain of this, but since it takes time to initiate a turn on a motorcycle (countersteer plus leaning), I doubt this is remotely possible in the available time. And even if it were, the motorcycle would likely hit the center divider before it could straighten out.

Thank you, this has made my day. I was just showing my girlfriend that rides as well the dangers of lane splitting at a delta over 15, I was estimating 80 mph from the looks of the car movement vs the bike pass.

 

[caideN]

Good info in this post. I see this a lot and I'll admit that I've done something similar a few times because the car in the HOV lane was going 40mph without anyone in front.

Watching videos like this tells me why the car in my situation was going 40mph. The speed difference from HOV to #2 Lane was so big that even the car driver was afraid someone might change lanes into the HOV thinking their car is a car that can speed up to 60 in 1 second.

Back to the video. If the bike was any lighter, I think the rider would've gone into the opposite side of the freeway and we all know how that would've ended.

 

[JakesKTM]

Dan's post nailed it but might I add:

The fact that the moto rider survived this poor lapse of judgment is far from relieving.

This may very well ruin his life. The financial losses will not be reimbursed by insurance and he may well end up in court both civilly and criminally. He was riding reckless, period. Video analysis by Dan was spot on. 75mph delta and 90mph pass.

His medical bills, those bills incurred by the other driver, his fines from reckless driving if the video ever surfaces, his exposure to lawsuits and possibly his career (depending on moral occupation) and such.....

It's not worth it!

Check yo'self ...........

 

[Holeshot]

Datadan rules! Good analysis Dan.

I'd only add one thing: The rider wasn't looking far enough ahead for merging cars for his speed. His brake light comes on about 5 feet after he passes the camera vehicle. The Pontiac changes lanes when he's next to the camera vehicle. That's a good amount of distance with no action.

 

[KazMan]

I think a lot has been said about the delta and rider technique. So some strategies I use when I am commuting/lane sharing which perhaps you all could provide feedback on as well.

1. It helps that I am a scardy cat so maintain a 10-15mph delta with slowest moving lane.
2) If it is a stretch with many on-ramps, I am very leery of cars trying to get to the commute lane.
3) I try and visually manage all gaps with cars on both sides. If there is a gap in stopped traffic it usually means someone is engaged in their phone or someone is trying to make lane changes.
4) When in the commute lane, I will maintain the right wheel track of cages as most people set their mirror up for that view. If I am in left track, they may not see me even more so with a car/truck in front and will cause the quick blind dart if there is a gap behind the vehicle. I believe that being in the left increases the ratio of close calls I don't want.
5) If a car is going well above the speed limit in the commute lane and the #2 lane is stopped or very slow. I maintain an extended distance behind and to the right so that cars may see me behind the vehicle. I will not pass even if they move over as I am more concerned with the #2 lane. Often times, I will just tell them to continue on by waving until such a time as I can pass and feel comfortable.

One of the things I did notice was that the car had it's blinker on. That doesn't make the execution of the lane change correct as current day drivers forget the part of "when safe to do so".

Also, the van had a visible gap with the truck in front and hit their brakes. Yes, they had a left rear brake light out, but a brake light came on (I think there is one up top also and I love those things) which would have made me go extra hyper alert.

As much as I can, I try and scan not only the lanes I'm sharing, but 2 lanes over so that I can see vehicles trying to make lane changes. Perhaps doing the Bay Bridge has been exception training ground for this as there is no commute lane and it's more wild west about which lane you can go to. But that strategy (and raining) has been very effective when I go to Sac or to the South Bay (880/101) on occasion for meetings.

:2cents

 

[Smash Allen]

I think enough has been said about the delta and rider technique. So some strategies I use when I am commuting/lane sharing which perhaps you all could provide feedback on as well.

1. It helps that I am a scardy cat so maintain a 10-15mph delta with slowest moving lane.
2) If it is a stretch with many on-ramps, I am very leery of cars trying to get to the commute lane.
3) I try and visually manage all gaps with cars on both sides. If there is a gap in stopped traffic it usually means someone is engaged in their phone or someone is trying to make lane changes.
4) When in the commute lane, I will maintain the right wheel track of cages as most people set their mirror up for that view. If I am in left track, they may not see me even more so with a car/truck in front and will cause the quick blind dart if there is a gap behind the vehicle. I believe that being in the left increases the ratio of close calls I don't want.
5) If a car is going well above the speed limit in the commute lane and the #2 lane is stopped or very slow. I maintain an extended distance behind and to the right so that cars may see me behind the vehicle. I will not pass even if they move over as I am more concerned with the #2 lane. Often times, I will just tell them to continue on by waving until such a time as I can pass and feel comfortable.

One of the things I did notice was that the car had it's blinker on. That doesn't make the execution of the lane change correct as current day drivers forget the part of "when safe to do so".

Also, the van had a visible gap with the truck in front and hit their brakes. Yes, they had a left rear brake light out, but a brake light came on (I think there is one up top also and I love those things) which would have made me go extra hyper alert.

As much as I can, I try and scan not only the lanes I'm sharing, but 2 lanes over so that I can see vehicles trying to make lane changes. Perhaps doing the Bay Bridge has been exception training ground for this as there is no commute lane and it's more wild west about which lane you can go to. But that strategy (and raining) has been very effective when I go to Sac or to the South Bay (880/101) on occasion for meetings.

:2cents

I agree with everything you said here :thumbup

Some may take exception with bolded number four, but my experience splitting LA traffic 20,000 miles over a few years has taught me the same thing.

I position myself in people's mirrors as much as possible all the while assuming they won't look. I am ready with a plan if it crosses into my lane. Whether my plan is to accelerate with the car and get to their driver window to show them that I am there, or back off the throttle and cede the space, it depends on the situation and the flow around me.

Putting myself into other driver's frame of mind (could I see myself through the mirror? Am I going slow enough I could see myself approaching? If I were driving would I want to jump into that gap?) helps develop a much broader situational awareness than just observing events as they unfold. By then it could well be too late!

 

[Enchanter]

I used to ride on the right side of the lane for the same reasons (placing myself in the mirrors of the cars in the lane to my right). Then I got hit. I've posted it on BARF many times, don't have the time to link it now. EDIT: found it.

Placing ourselves closer to the hazard, is rarely the right choice. As motorcyclists we constantly hear and talk about 4-wheel drivers not using their mirror, why is this situation different?

Google "how to adjust your car mirrors" and you will discover that we aren't in their mirrors when in the right side of the lane. Don't just read this link, go set up your mirrors and see for yourself. You will be surprised.

We should ride in a pro-active manner by maintaining the most time and space we can to the threat(s). Consider that riding in a manner to inspire people to not change lanes is riding in a reactive manner. Action beats reaction. It applies to motorcyclists too.

I realize that many riders feel that they have ridden on the right side of the lane and survived. You may have had some success with cars noticing you and that re-enforces the idea that it is the right thing to do. But when you find the driver that truely doesn't look, or yanks the wheel over and changes lanes aggressively, you are going to want more distance between them and you.

As motorcyclists, we cannot bank on our superior (physical) skills to save us. We need to relay more heavily on our minds. Riding on the right side of the lane is relying on physical skills more than mental skills.

 

[KazMan]

Thanks for that perspective Enchanter.

For me, riding in the right track actually allows me to use their mirrors to identify what their attention or distraction may be. It allows me to see in modern autos if their mirror lit up. It often times allows me to see that they have recognized if I am there, and I can move on to can I pass safely or do they feel the need to interfere with my progression through.

Not all do, but at least I can see that intent as well as it's usually recognition followed by a slide to narrow the gap. Mostly trucks for some odd reason on the Bay Bridge.

So I guess, effectively, I am using those tools provided to me, to help me assess what may occur and enhance my defensive strategy. I very rarely go on the offensive, because 9 out of 10 times, that has to do with more speed and higher deltas.

Of course this is when I am sharing lanes 1 with 2. More or less the opposite when I am over on the other side which is very rare so I can eliminate on/off ramp chaos. So I 100% agree with the using the mental side during lane sharing.

 

[DataDan]

4) When in the commute lane, I will maintain the right wheel track of cages as most people set their mirror up for that view. If I am in left track, they may not see me even more so with a car/truck in front and will cause the quick blind dart if there is a gap behind the vehicle. I believe that being in the left increases the ratio of close calls I don't want.

Some may take exception with bolded number four, but my experience splitting LA traffic 20,000 miles over a few years has taught me the same thing.

I position myself in people's mirrors as much as possible all the while assuming they won't look. I am ready with a plan if it crosses into my lane. Whether my plan is to accelerate with the car and get to their driver window to show them that I am there, or back off the throttle and cede the space, it depends on the situation and the flow around me.

I disagree with #4.

The tradeoff is:

More likely to be seen in the adjacent tire track (right side of lane with traffic in lane to the right).​

vs.

Easier to avoid a crash in the opposite tire track (left side of lane with traffic in lane to the right).​

I think riders overestimate their ability to avoid a crash in the event of an incursion when in the adjacent track. Traveling 15mph faster than the next lane, an incursion that begins when you're 30ft behind the offender's back bumper is an unavoidable crash. At 30mph faster, you're vulnerable at a much greater distance and probably will not be seen.

And I think riders underestimate the protection afforded by 12ft lane width of space cushion. A fast lane change takes 2 seconds. In the event of an incursion 30ft ahead when traveling 15mph faster, you can avoid a crash simply by maintaining speed and position; you'll overtake before the lane change is complete. Traveling 30mph faster than the next lane, you can overtake from nearly 90ft behind.

 

[planegray]

I disagree with #4.

The tradeoff is:

More likely to be seen in the adjacent tire track (right side of lane with traffic in lane to the right).​

vs.

Easier to avoid a crash in the opposite tire track (left side of lane with traffic in lane to the right).​

I think riders overestimate their ability to avoid a crash in the event of an incursion when in the adjacent track. Traveling 15mph faster than the next lane, an incursion that begins when you're 30ft behind the offender's back bumper is an unavoidable crash. At 30mph faster, you're vulnerable at a much greater distance and probably will not be seen.

And I think riders underestimate the protection afforded by 12ft lane width of space cushion. A fast lane change takes 2 seconds. In the event of an incursion 30ft ahead when traveling 15mph faster, you can avoid a crash simply by maintaining speed and position; you'll overtake before the lane change is complete. Traveling 30mph faster than the next lane, you can overtake from nearly 90ft behind.

For me, the left track/right track choice is made based on:
1) the size of the gap I'm in
2) The speed of traffic
3) whether or not the traffic is "accordioning" (slowing down or speeding up)

If the traffic is fairly dense and slow, I stay on the right side.
Once speed is above 40mph, gaps are large or gaps are changing in size due to traffic speeding up/ slowing down ( like an accordion) then I'm more prone to riding in the left track

 

[Smash Allen]

And I think riders underestimate the protection afforded by 12ft lane width of space cushion. A fast lane change takes 2 seconds. In the event of an incursion 30ft ahead when traveling 15mph faster, you can avoid a crash simply by maintaining speed and position; you'll overtake before the lane change is complete. Traveling 30mph faster than the next lane, you can overtake from nearly 90ft behind.

I wonder how much more time you are afforded by being in the left 1/3 of lane versus right 1/3 of lane?

You gain around four feet of additional cushion on top of the six feet (two feet from car wheel to lane marker, four feet from marker to right 1/3 of lane).

Going by your numbers you have a full second before a car makes contact with you when in right 1/3 of lane (12ft/2s=6ft/s lateral movement).

So, it looks like in the left 1/3 of lane you would have another half a second or so before contact is made. 50% more reaction time is significant, no doubt. Even still, it feels like I'm doing something wrong camping in the left part of my lane. I think I will periodically 'wander' from the left 1/3 to the right 1/3 to make me feel better

 

[KazMan]

Point of clarification please. We are talking about lane sharing correct? In traffic? And not about travelling down the freeway with open lanes on either side?

So when sharing, some of you move from the left side of the lane, to the stripes, split, and then move back to the left side of the lane?

Don't know why this just popped into my mind.

 

[Enchanter]

Given the video in the first post, it's a bit of both. The rider shared past a vehicle into a huge gap.

When I laneshare in the #1 lane, and ride into a large gap (2 car lengths or more) I move into the gap. My speed differentail is slower than most, so it's easy for me and doesn't look like a swerve.