In the summer time in various forest towns in California, some of which have had major fires recently... I see probably 20 grass fires a year. All of them start next to the road.

I actually think the perpetrators are not that we have 1000 smokers, there are probably just a few REALLY bad people that don't care. They are also the kind of people that if you started to put up signs about smoking and fires, they would start throwing lit matches out the window.

Not that I have any sympathy for smokers, but there are a lot of anthropogenic sources of ignition. Cars dragging metal, and hot catalytic converters are a couple. Electric lines that frequently run along roads are another. And campfires and ordinary cooking fires can spark a wildfire; homeless people tend to live near roads and overpasses.

The fact that we don't have more arsonists in California is one thing that gives me faith in humanity.

The huge California Carr fire was caused by a flat tire ...

https://www.businessinsider.com/california-fire-caused-by-fl...

> [...] The fire was first ignited on July 23, after a trailer's tire blew out and the rim made contact with the pavement, [...]

Not that surprising. Lumber doesn't catch fire that easily (hence fire starters).

I saw it by my own eyes when I was child. Old wooden fence started to burn after cigarette butt landed at it in hot summer. Wood was dry and hot in direct light. I saw little smoke first then smoke disappeared, then, after couple of minutes, clean fire.

You saw the combustion equivalent of being bit by a shark and struck by lightening at the same time. Except in exceptional circumstances where the wood is highly flammable (like very dry and probably a little bit rotted wood that's at 150F+ from sitting in the sun), something like a cigarette butt or a lit match is not enough to catch lumber on fire without some other easier to ignite material in between as a stepping stone.

You seem to be quite mistaken: https://www.fire.nsw.gov.au/page.php?id=327

Your link deals with cigarette butts igniting brush on the roadside and hay in a lab simulating roadside conditions, not lumber. Nobody here is claiming that cigarette butts can't light dry brush on fire. I am claiming that in less than "freak accident" or laboratory conditions it is basically impossible to ignite lumber with a cigarette butt unless there is something (like dry brush) in between.

Edit: Based on the down votes I'm illiterate, I'm wrong or this is Reddit.

Current cigarettes have additives in the paper so that they go out easily themselves.