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Today I’m going to write about crime.  This comes up often enough that I thought I’d have to start looking at it sooner or later,.  The standard trope is that no one rides or wants to ride transit because of fear of crime.  Disarmed by this claim, I’ve been left flat-footed in the open, asking “is crime really more likely on transit?”

It seems intuitively obvious.  You get in a confined metal box with few exits, and jt seems obvious that you will fall prey to the predators among us.  Easy pickings.  Get me out of this box!

So I decided to look at the national data on the matter, specifically to aster the question, how likely am I to fall victim to a crime each and every trip- I take, and how does this compare to my chances of falling victim to a crime just leading my life out in public?  To answer this , I used nicely compiled time series tables at http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/national_transportation_statistics/html/table_02_38.html and http://www.fbi.gov/about-us/cjis/ucr/crime-in-the-u.s/2010/crime-in-the-u.s.-2010/tables/10tbl01.xls.  I also had to figure out how many trips were taken on transit.  Luckily, this sort of this recorded too, at http://www.apta.com/resources/statistics/Pages/ridershipreport.aspx.  

Finally, I needed a way to equalize the data.  Most transit passengers take two trips per weekday, because most transit trips are for work commutes.  But how to compare this with national crime stats?  Typically, annual crime rates are calculated “per 100k population”.  In other words, the crimes are divided by the population, and that thankfully tiny number is multiplied by 100k to bring it close to 1.  Traffic fatality rates are normalized in much the same way, except the multiplier is 100 Million passenger miles traveled.

So I “controlled” annual stats by multiplying the population by 365 (days in a year) time 2 (trips per day).  This got the everyday life crime stats in line with the transit stats.  Maybe even a little more, as most transit passengers don’t ride on the weekends.

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Looking at the results, we see some consistent patterns.  First, crime has gone down sharply since 1995.  That has nothing to do with transit versus life, but I just thought y’all should know about that before you get nostalgic about the good old days.  The good old  days are happening right now.  Second, Transit is a heck of a lot safer than Life, at least nationally.  Your transit system may vary, but this average indicates that the perceived risk is out of touch with the real risk.  Transit has actually been getting safer twice as fat as life, if you compare 1995 with 2010 crime rates.

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If you are still making bargains with Transit, the safest mode to take is constantly the bus.  This is probably because the bus is the most intensely policed, and frequently observed of the transit modes shown here.  If the cast of characters is changing every quarter mile, and the ration of bus riders to drivers, in the same vehicle is under 40, it is very hard for a criminal to be assured of a clean mark.  This is especially interesting considering that the bus is considered the most plebeian of the transit modes.  Many transit advocates have denounced the rail transit construction as a siphon from democratically dispersed bus routes expensive, focused rail transit corridors.

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At the other end, light rail seems to be the riskiest.  The converse of my theory about vigilance would hold here, with fewer stops and isolated cars behind the lead car.  I wonder if the majority of these crimes happen at long or short stop interval trains.  My hypothesis would of course be that the crimes would happen in the  rear cars, ways form the eyes of the driver and their communication with central control.

Transit is one of the most heavily policed spaces we ever get to inhabit, even mores than traffic, I expect.  I have a large ungainly spreadsheet of this sort of data, and I’ll be following up with as much data and inference as I can muster.  Crime stats just barely scratch the surface of the debate about transit and crime, as you know.

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