Later On

A blog written for those whose interests more or less match mine.

Here are the reasons not to lock up people who come to shelters

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Radley Balko has a clear explanation:

Polk County, Fla., Sheriff Grady Judd is getting some heat for the tweet below, posted Wednesday morning. And rightly so.

Most of the criticism of Sheriff Judd’s tweet has rightly focused on its implications. If residents of Polk County heed Judd’s warning and stay away from shelters, and if Hurricane Irma hits Polk County with all the force and fury that’s expected, it seems likely that some of those people will be injured or killed. It’s an incredibly irresponsible thing to have posted publicly, and it’s indicative of a sheriff who’s more interested in being punitive than in public safety.

But I want to dig a little deeper into this, and look at who it is that Sheriff Judd’s tweet is targeting. For most people, I suspect the phrase “outstanding warrant” conjures up an image of someone accused of domestic abuse, an escaped felon or someone who jumped bail after an arrest for a serious offense. But the vast majority of people living under outstanding warrants got to that position because of one or a series of traffic citations, followed by an escalation of fines and fees stemming from an inability to pay.

The common refrain from people defending the sheriff on social media was some version of “If you can’t handle the punishment, don’t break law.” This was also a common response to the post-Ferguson reports (including here at The Watch) on the way fines and fees have been devastating low-income people in St. Louis County, Mo., and to similar reports about oppressive fines and fees in other places across the country.

In fact, it’s a common enough response that I think it deserves a detailed deconstruction. So here are a few things to keep in mind when we talk about people who have outstanding warrants stemming from low-level offenses.

— Speed limits are arbitrary, counter-productive and almost universally too low

Most of us speed. A 2008 Purdue University survey of Indiana drivers found that “21 percent thought it was safe to drive up to 5 mph over the speed limit, 43 percent thought it was safe to drive up to 10 mph over and 36 percent thought it was safe to drive up to 20 mph over the speed limit.” A 2002 study found that two-thirds of drivers said it was safe to ignore posted speed limits. Gary Megge, a lieutenant with the Michigan State Police who has researched speeding for much of his career, estimates that only about 10 percent of drivers strictly observe speed limits.

There’s good reason for this. Most posted speed limits are far too low. There’s a perception that most motorists will always drive 5 miles to 10 miles per hour above the posted speed limit, no matter what it is, on the theory that most cops won’t take the time to pull them over for such a slight infraction. But that perception is wrong. According to a 1992 study by the federal Transportation Department, most drivers adjust their speed according to road conditions. Posted speed limits only factor into the equation if there’s a speed trap nearby. More importantly, there’s little correlation between traffic fatalities and raising or lowering the speed limit:

The results of the study indicated that lowering posted speed limits by as much as 20 mi/h (32 km/h), or raising speed limits by as much as 15 mi/h (24 km/h) had little effect on motorist[s’] speed. The majority of motorists did not drive 5 mi/h (8 km/h) above the posted speed limits when speed limits were raised, nor did they reduce their speed by 5 or 10 mi/h (8 or 16 km/h) when speed limits are lowered. Data collected at the study sites indicated that the majority of speed limits are pos[t]ed below the average speed of traffic. Lowering speed limits below the 50th percentile does not reduce accidents, but does significantly increase driver violations of the speed limit. Conversely, raising the posted speed limits did not increase speeds or accidents.

The authors studied a wide cross section of roads and highways, and found that on 90 percent the roads they studied, at least half of motorists were driving faster than the posted speed limit. These results have been confirmed in subsequent studies. For example, a 1997 study of Michigan roads by the consulting group TranSafety, Inc., concluded that:

 Compliance with speed limits was not necessarily an accurate measure of safety. Although more crashes occur in urban areas, as can be expected from congestion and the need to react to other vehicles, drivers seem to choose speeds similar to the design speeds for different types of roads. The research suggests that lowering speed limits arbitrarily does not affect traffic safety. Speed limits and speed zones would be more effective if they were based on geometrics, traffic characteristics, and safety benefits rather than popular conceptions.

Most traffic accidents happen not when drivers speed, but when motorists are traveling at widely varying speeds on the same road. If we’re going to have posted speed limits — and it’s not entirely clear that we should — the consensus among the engineers and academics who study this stuff is that the the optimal speed for safety and efficiency is known as the “85th percentile speed,” or as a Michigan State Police guide puts it, “the speed at or below which 85% of the traffic moves.”

But few states abide by the rule. That 1992 DOT study looked at 22 states and found that the average speed limit was at the 45th percentile, and on average was between 5 miles and 16 miles per lower than the optimal speed limit. The study found that when speed limits were lowered even more, accidents didn’t decrease, but more motorists sped. When the artificially low speed limits were raised, accidents decreased, and the motorists at the highest percentiles did not significantly increase their average speed to compensate.

It’s true that if the speed limit everywhere were 20 miles per hour, and everyone abided by it, the roads would be immeasurably safer. But that isn’t going to happen. And we simply don’t have the resources to catch every speeder. Even the most aggressive enforcement won’t catch everyone. In fact, more aggressive enforcement may make the roads lesssafe by altering psychology of drivers. As noted, most motorists are pretty good at finding a speed at which they can safely drive, given the road conditions at the time. But in areas of aggressive enforcement — think of speed traps where the posted limit may suddenly drop — there’s a tendency to stop relying on instinct and peripheral awareness, and spend more cognitive energy looking for speed limit changes and waiting cops.

So the empirical evidence overwhelmingly states that we’d be a lot safer if most towns and cities raised their speed limits to the rates at which most motorists drive.

Why won’t they? Because . . .

— Local governments need people to break traffic laws. They’ve grown dependent on the revenue.

Michigan is one of the few states that tries to implement the 85th percentile approach. But getting local towns and municipalities to go along has been a struggle. The blog Price Economics interviewed Lt. Megge about the problem in 2014. . .

Continue reading.

Written by Leisureguy

8 September 2017 at 10:09 pm

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