Can someone explain the red liquid spray patterns that appear on the asphalt of Southern California freeways?

March 26, 2004 7:48 PM

Can someone explain the red liquid spray patterns that appear on the asphalt of Southern California freeways? [more inside]

A few times a year, I will come across a delta-shaped liquid dispersal pattern on Southern California freeways, usually on the 101 through the San Fernando Valley. The delta expands in the direction traffic flows, starting at a point-ish place and fanning outwards. It's what you might expect to see if you dropped a can of paint off the back of a truck at speed. But if it is "paint off a truck", why is it only red (if there is not selective memory involved here); why not other colors? Pure chance?

Of course, the first thing my mind jumps to is "blood", but the arguments against it being donorcycle street pizzas are [a] I don't think blood would stay that deeply red and [b] I don't think it would be that tenacious on asphalt. But I really don't know what I'm talking about, as my only experience with blood pools is that bastion of scientific integrity CSI (and yes, that's something you'd need a TV to get. :)

I'm usually pretty good at online research, but I don't even know where to start on this one (many of my guesses, not even using the word blood, take me to horror fiction or death fetishism.

Completely unrelatedly, would a U.S. resident here like a free, sealed packet of heirloom flowering tobacco seeds from Seed Savers Exchange? It was included by accident in my recent shipment of seeds, SSE doesn't want them back, I'm surely not going to grow them, and I'd experience more than $0.37 worth of guilt throwing them away. I don't want your address or anything, I'll send to a POB, PMB, your employer, a maildrop, whatever.

posted by quarantine to home & garden (5 comments total)

/derail

that bastion of scientific integrity CSI

actually, CSI's laughable aspects are the sheer speed -- DNA results comin' up in a few minutes, come on... -- at which the lab operates, and the amount of actual police work (dealing with witnesses, et al) done by the CSI team
and of course it's unbelievable how good everybody looks.
but the science stuff is not badly done if you consider it's just a popular, megacorporate TV show -- they have good scientific consultants, at the very least.

and I'm a fan of the show, too.

posted by matteo at 8:01 PM on March 26, 2004

I'd bet on roadkill. I've seen astonishingly large sprays of old blood from small and mid-size mammals (dogs and raccoons and stuff that size, judging by the lumpy pile on the side of the road). And -- on roads I'd drive every day -- I've seen them last a good couple-few weeks.

Shows up a lot more on concrete surfaces than actual asphalt. Though asphalt that's a bit grey and dusty would show it some.

(there was lots of roadkill in Chatham County, NC)
posted by ROU_Xenophobe at 11:31 PM on March 26, 2004

Hm. Well, consider that lots of stuff probably falls from cars, but only some of it leaves permanent marks. All the marks you see might actually be paint cans falling out of contractors' pickup trucks. Statistically, it may not happen often, but if every instance leaves a permanent mark, soon enough you'll be seeing them everywhere.
posted by scarabic at 11:58 PM on March 26, 2004

If no one has spoken for the tobacco seeds yet, I would enjoy trying them out for the experimental experience. Email in my profile. I'll even reimburse you for the stamp.
posted by Alylex at 12:44 AM on March 27, 2004

Thanks, everyone, that's helpful. And you're right, ROU_Xenophobe, it's concrete, not asphalt -- certainly more grey than black.
posted by quarantine at 11:00 PM on March 27, 2004