>Picture four lanes with four vehicles. You decide to go right down the middle. The outermost vehicles change, being replaced by larger vehicles, but the innermost vehicles haven't seen you.

This might be part of the disconnect here. You aren't "sitting" next to cars, you are passing them. If you aren't actively passing cars, you aren't splitting and should get in your own lane.

A rule of thumb is that you should be passing cars in about a second or so. So any "crunching" would have to happen within that second of time, or the motorcycle will be out in front by the time any contact would have been made.

But in reality that just doesn't happen. Mirrors stick out, and it is extremely rare for 2 cars to get close enough for their mirrors to touch, let alone have a mirror touch the other car.

But also cars just don't go from driving straight to instantly swerving toward another car in the next lane, they have "tells", they start drifting from the driver not paying attention, they act erratically, they have turn signals.

A safe lane splitting scenario that I do is like this.

* Cars are in both lanes, fairly close together so there is no room for people to try and shoot across to fill a gap in the other lane (if the cars are "staggered" like 2 sides of a zipper, that is a dangerous situation that I don't split in, because that is when people are likely to try and shoot into the next lane without any warning!)

* Cars are traveling about 15 to 30mph in both lanes, and there isn't a large speed differential between them (again, if one lane is going 15, and the other 30, people in the 15 lane are likely to try and shoot over to get in the "faster" lane, and sometimes people in the fast lane will try to shoot in to the slow lane so they can get off the next exit)

* I can see several car lengths ahead of me on my bike (bikes sit higher than cars, so you can often see much further ahead and can see over many cars. This also means that splitting is not okay on curves, hills, or when there are big trucks obscuring your view ahead, or if the drivers ahead are staggered in their lanes blocking a nice clean path)

In that situation, I go about 10-ish mph faster than the cars around me (a rule of thumb is you should be passing a car within a second, that equates to around a 10mph speed differential), and while doing this i'm looking at tail lights 3 or 4 cars ahead to see if anyone is stopping suddenly, turning, has a signal on, or is doing anything weird. if at any point things don't look good for splitting any more, I slowly drift back into my lane, slow down to match speed with that lane, and i'm no longer splitting.

If at any point things go really bad, say someone starts getting over toward me, or there is an accident ahead of me or next to me, I grab the brake and very quickly the bad stuff will pass me. And if it doesn't in time, then I'll get munched! That means yes you'll have to go through the insurance stuff for the scrapes and dents in the side of your car, and I'll probably have a broken ankle or a small neck injury, but i'll be alive. Contrast that with the alternative of not splitting where that same accident happens (because if you are drifting into another lane with another car in that lane and you don't see the biker in time, chances are you aren't going to see the car in time either and will smack into it), and when you slam on the breaks because of that, I run into the back of your car at 30mph and am in a LOT worse shape than i would have been in the splitting scenario.

But just like how we have lane markings for a reason, in many areas we also have laws that allow splitting for a reason, and you can't selectively pick and choose which laws you want to follow!