How to model the accident rate on a certain stretch of road
May 7, 2012 2:19 AM Subscribe
How could I approach modeling the number of accidents on a certain stretch of road? I've got some semi-ecological approaches in mind but no idea if they're workable. Are there standard approaches to this sort of problem?
posted by col_pogo to Science & Nature (9 answers total) 2 users marked this as a favorite
Recently I've been traveling a certain 250 mile stretch of road quite a bit. It's reasonably dangerous--one wet, drunken three-day weekend several years ago 27 people died on it--and I've found myself wondering what the serious accident rate is. (No lives will depend on my answers; nor am I doing this for a school project. This is all about curiosity.)
It occurred to me that I've traveled this road--let's say 30 times in 6 months. That's effectively 30 "samples" (or "transects," maybe?), and I've seen the remains of one serious accident. Could I use these samples to make an estimate of the serious accident rate?
I gather ecologists and zoologists do something similar when doing animal censuses: they do a transect, count up the animals they see, then make some assumptions about how many they're missing and derive an estimate from that. Others look for animal leavings (dung, animal carcasses, etc) and extrapolate from there. Could I do something similar in this case with the wreck I saw (and those I didn't)?
(Of course my "transect" is different in that cars don't travel outside the transect; I'm only interested in accidents along the transect itself.)
My thinking is that the remains of a serious accident will have a "half-life" based on how long it takes to get a tow-truck service out to remove the wreckage. I'd guess that 50% of remains are gone in a day or so: support can be called out relatively quickly as there are five towns along this 250-mile route, spaced fairly evenly (two at the termini, and then every 50 miles in-between), but it might take a while for them to muster up removal services, especially for big wrecks. The one I spotted was a burnt-out tanker and a delivery van that appeared to have had a head-on collision. I assume that large wrecks like this would have been difficult to move.
So could I use my "samples," my one observation, and some assumptions like the "half-life" of a wreck to produce a sensible estimate of the accident rate?
I don't need this data: I'm mostly just curious about whether and how my line of thinking could be used to make a reasonable estimate of the accident rate. Would it work? Are there other, better ways of approaching this kind of modeling?
Full workings of the problem, tips, examples, links to articles and books on modeling technique would all be very welcome.