Thursday, 6 August 2009

Speed Limits: The Way Ahead?

A JERSEY politician has proposed increasing speed limits in green lanes to 20 mph - but doing much more to enforce the limit and penalising those who break it. Deputy Daniel Wimberley has written to the review group looking at Islandwide speed limits, welcoming the project and saying that many of his parishioners have called or written to him about the issue of speed. He added said that raising the green lane speed limit from 15 mph to 20 mph would be sensible - but only if it was properly enforced. He said that would allow the States to set up three easy and consistent speed bands: 20 mph for urban roads, village centres, near schools when pupils are around, and all narrow roads; 30 mph if there are frontages on one or both sides of the road; and 40 mph everywhere else.(1)

Why do people routinely ignore speed limits? Part of the reason has to be the confusion of speed limits, which are dotted over Jersey like a patchwork quilt that has been worked on by many hands; some of these are sensible limits, but where restrictions have been put in place, the absurdity of the limit on the roads just out of the restricted zone has not been considered. This blinkered approach gives rise to roads like St Brelade's Bay being mostly 20 m.p.h., while La Marquanderie, Mont Gras d'Eau, and the steep hill by the back of St Brelade's Church are all left at 40 m.p.h. It is like a jigsaw where one person concentrates on finding their piece, but ignore the bigger picture.

But there is also an element of psychology at work here. Margaret Raymond examined how mostly law abiding people still break particular rules. She looks at law-abiders, who comply with all laws, and law violators, who willfully refuse to comply with laws, and suggests there is a third category:

There is a third category of actor, and most people fall into that category. This category contains people that are persistent violators of criminal prohibitions, violation of which is not ordinarily stigmatized or subjected to social or legal sanction at the levels where prohibitions are routinely violated. I call these offenses, which otherwise law-abiding actors routinely commit, penumbral crimes.

A penumbral crime is a criminal act defined by a high level of noncompliance with the stated legal standard, an absence of stigma associated with violation of the stated standard, and a low level of law enforcement or public sanction. These factors, however, do not persist at all levels of violation; the law's application in effect creates a "penumbra" of accepted behavior that, while unlawful, will not ordinarily be sanctioned or stigmatized. Beyond the "penumbra," enforcement and stigma resume, and ordinary criminal rules apply. Penumbral crimes are interesting, in part, because people who define themselves as law-abiding--indeed, people who pride themselves on being so--regularly violate these laws. (2)

A person who speeds is unlikely to commit murder simply because his experience with flouting speeding laws has obliterated his commitment to the social norm of law obedience. In fact, one of the interesting things about penumbral crimes is that individuals who commit them continue to view themselves as observers of the law obedience norm even in the face of their law-violating behavior.

This is pertinent for Daniel Wimberley's call for law enforcement, because one of her main examples is speeding:

Imagine that you are driving on an interstate highway. The posted speed limit, as in many parts of the country, is 65 mph. How fast are you driving? If you answered "the speed limit," you are in a distinct minority. Drivers in the United States rarely obey speeding laws. Surveys that ask drivers how fast they drive indicate that most admit to speeding. About two-thirds of all drivers report that they at least occasionally exceed the maximum speed limit on the roads they regularly drive, while 30% of drivers report that they regularly tend to drive faster than other motorists on the road. Self-reporting being what it is, research that assesses whether drivers actually observe speed limits reflects even more significant noncompliance: in one study, 70% of vehicles exceeded the speed limit. Anecdotal evidence sets that level even higher.(2)

Speed limits are therefore often set to allow for this kind of variation, because it is impossible to police all roads. The limit may be set where it is to enforce the penumbral limit. For example, taking the local context, you do not set the speed limit at 20 because you want people to drive 20; you set the speed limit at 20 so that motorists will exceed the limit by 5 mph rather than setting the speed at 25, the penumbral limit. Someone going through a speed limit of 20 at 22 mph will be taken as being within this limit, while going through a 20 mph zone at 30 mph is outside the limit and will incur a fine.

When speed traps are introduced to enforce speed limits, the literal nature of the speed trap (such as with an automated speed camera or a police officer with a speed gun) causes a clash with the culture of penumbral crime, and outrage at what has happened. It is a culture shock.

The widely recognized perception that speeding laws are not literally enforced produces an interesting phenomenon: speed traps. The belief on the part of drivers that they can speed moderately with impunity creates an opportunity to surprise them with literal enforcement. While vigorous literal enforcement of a speed limit produces substantially greater compliance with that limit than is commonly observed, at least among repeat users of the road, it also produces indignation and outrage that indicates more than disappointment at being apprehended. It suggests, instead, a clear sense that the law enforcement activity that takes place at these stops is somehow wrongful or illegitimate. (2)

To counter this shock, there is normally a degree of penumbral variation build into speed traps.

(a) Public officials often state confidently that no one was ticketed unless they exceeded not the speed limit, but a range above and beyond that posted limit. The speed indicator on a car, after all, is rarely a digital display, and like a clock hand, may vary slightly depending on the position and height of the driver in relation to it.

(b) Signage is introduced (such as speed camera warnings) to warn drivers that speeding laws are enforced strictly in the area. This confirms what most people understand: that enforcement is so rarely literal that it would be unfair to enforce the speeding laws strictly without prior notice.

How does one enforce compliance against penumbral crimes? Margaret Raymond suggests several possibilities. One is to ignore the problem, which she says gives the message that "lawbreaking behavior is in some respect preferable to law-abiding behavior." Another is to enforce the law literally. This has a problem with resource allocation: "Jurisdictions may be unable or unwilling to assign law enforcement and judicial resources to pursue a high number of offenders simply to change the common perception that these crimes are unpunished at the literal, rather than penumbral, levels." She also notes that people become especially resentful of what they consider to be an unjust and petty enforcement of the law, which rather than creating a mindset where people want to obey laws, creates instead an attitude of negativity towards legal norms, which leads to a collapse of compliance and reversion to old habits just as soon as the enforcement is removed.

In "Psychology and Policing", the authors note that:

A number of studies have shown the effectiveness of direct police operations on speed behavior. Hauer, Ahlin, and Bowser ( 1982) reported decreases in traffic speeds of 23% to 28% within 2km of a visible police operation. Armour ( 1984) also noted a reduction in the proportion of drivers exceeding the posted speed limit at visible police sites. Both these authors reported, however, that these speed reduction benefits only lasted within a small distance (or time) of the test site, a phenomenon known as a "halo effect." (3)

Speed cameras can enforce compliance, but not only do they engender resentment, but they also do not deal with the main problem of attitude to speed limits, so that motorists modify their behaviour where there are known cameras, but revert to penumbral limits outside that frame. However, the authors do note that "site-specific use seems to have some marginal benefit as a "black-spot" measure."

More effective can be a campaign (which may involve a degree of enforcement) which involves norm alteration and stigmatisation, especially where the consequences of breaking a norm can be life threatening, as with drunk driving. Whether this is enough for speed limit enforcements is another matter, but certainly a campaign against driving too fast, and a focus on the personal cost of doing so may help, even if it is not the full solution.

But her main suggestion is to introduce what she calls "Penumbral Statutes for Penumbral Crimes". This is how she sees this as working:

One approach to this problem would be to adopt a statute which memorializes the existing regime more closely. Such a statute would set a range of appropriate behaviors. In the speeding context, such a statute might look like this:

Speeding. A person is guilty of speeding if s/he drives more than

(a) 5 mph over the speed limit on a road where the speed limit is 30 mph or lower; or

(b) 10 mph over the speed limit on a road where the speed limit is greater than 30 mph.

The advantages of such a prohibition are evident. First, such a statute poses no challenge to the law obedience norm. Most drivers engaging in typical penumbral behavior would be obeying the law and the law defines the crime as they and the law enforcement community understand it. The discontinuities created by penumbral crimes are thus avoided. While the law does not increase compliance with the original statute, compliance with the new statute would be significantly higher since the statute reflects the way most self-described law-abiding people actually behave. Moreover, communication of the required standard is significantly clearer. In the ordinary penumbral crimes situation, some additional quantum of behavior above and beyond that defined in the statute is necessary to run afoul of the criminal prohibition, but it is not necessarily universally apparent what that behavior is. Use of a statute that makes clear what conduct will actually be subject to sanction solves the problem of fair communication. (2)

(2) Penumbral Crimes, Margaret Raymond; American Criminal Law Review, Vol. 39, 2002.
(3) Psychology and Policing. Neil Brewer, Carlene Wilson (1995), p52


Anonymous said...

This penumbral compliance idea highlights what is going wrong with justice in society recently. The forces of law and order are getting more draconian in their enforcement of the letter of the law and losing the chance of the much greater justice that applying the spirit of the law brings.

They do this by relying on the verdict of a mechanical radar gun or speed camera to demonstrate that the law is broken and to provide rock solid evidence that it has been done so. The whole point of speed limits is to make the roads safer than they otherwise would be - NOTHING ELSE.

In my submission to the TTS speed limit review I suggested that (apart from green lanes) speed limits were generally 5mph too slow, given that we now have (almost mindless) mechanical compliance with a set figure. This is the "penumbral" concept. Thus I suggested 45 mph for Vic Ave and the coastal section of the 5 mile road; 40 for general ex-urban roads; 30 mph for urban areas and narrow, visibility restricted country roads and 25 mph for village centres and outside schools (during active periods).

Driving through St Peter's Village at 20 is excruciating for any driver apart from the super-incompetent. One's attention wanders at that speed! - it is surely reduced attention which is far more responsible for causing accidents than the actual speed.

TonyTheProf said...

A friend has also supplied some useful information about Denmark:

In Denmark they use speed guns/cameras, then they

a) take the instrument variance (or somesuch) off the reading

b) tell you by what % you were over the limit

c) have a scaled set of fines relating to that %

So if you drive at 35 in a 30 limit, your fine is the 10-20% fine, the same as if you drive 150 in a 130 limit.

Using the % means that you don't need to have different numbers / rules for the different limits. So fines are automatically harsher eg near schools, where the limit is lower.

I don't believe they contact you at all if you are under 2%? over the limit.