Legislating Under the Influence

I am a little cautious about PM Harper's latest drive (sic) to allow the police to perform drug tests on individuals at roadside DUI stops. Just to be clear, I am not suggesting that drug impaired driving is a good thing. My cautious approach to this is about motivation and incentive.

Motivation.
I have to first of all question what the motivation behind this intiative is. Is drug impaired driving a significant cause of accidents? What do the data say? Well there are not a lot of data on the rates of driving under the influence of drugs other than alcohol. There are studies from the US and Australia that show illicit drugs, in combination with alcohol are detectable in anywhere from 10% to 20% of people arrested for alcohol related DUIs. The Consultative Document from the Government of Canada states that Section 253(a) of the Criminal Code makes it an offense to operate a motor vehical while while your ability is impaired by the presence of alcohol or other drugs. Section 253(b) however does not establish legal limits for drugs other than alcolol detected in the blood.

But there are problems with this, and some of them are right in the same Consultative Document. First and foremost, there are no data to link a particular level of drugs other than alcohol in the blood to a level of impairment to operate a motor vehical. In fact, some drugs, such as caffeine and amphetamines actually improve alertness and responsiveness. This is one of the reasons that the US Navy and Airforce routinely gives amphetamines to fighter pilots on long patrol missions. Truck drivers also routinely dose with both or either caffiene and amphetamines. Other drugs such as canabis, while they impair your motor functions, they actually make you drive more cautiously and SLOWER. That doesn't mean you should smoke up before driving.

The test for many drug detect not only drugs that are active in your system, but the presence of the drugs in your system for days, weeks or months after use. A typical test for canabis can detect use as long as 90 days in the past - well past the point where it impairs your driving. If the experience from the world of sports is any indication, drug tests are also notoriously inaccurate. False negatives and false positives are common place.

Finally, there is also little need to put in testing for drugs. A roadside sobriety test detects impaired function - regardless of the intoxicant. This gives law enforcement officers all the tools they need to immediately get impaired drivers off the road. In the end, it is the impaired abilty to operate a motor vehicle that we want detect, not the presence of some compound in your blood stream.

So if there is no known crisis of drug impaired driving, the test are inaccurate and imprecise, and no evidence to link a detectable level of drugs to a level of impairment, then what is the motivation for this change to the criminal code? It is nothing more than a bone thrown to the conservative base to show that the new Conservative government is tough on crime - unlike the soft on crime liberals.

Incentives
Testing for drugs raises the stakes for a DUI offence. One of the reasons that the 24 hour roadside suspension is so effective is that it removes any incentive to avoid, resist or fight prosecution or to mask detection. The immediate suspension gets the driver off the road - ending his/her risk to the public, and saves the courts the costs of prosecuting the large volume of cases that would otherwise be litigated to the bitter end. Adding drug testing to the mix, with the above mentioned inaccuracies and uncertainties, would virtually assure long and costly prosecution.

Arbitratry limits are generally ineffectual as behavioral incentives. If there is no connection between the indicator of a bad behavior (drug levels in the blood) and the behavior that we are trying to prevent (impaired driving) then people tend to simply accept the risk of getting caught because it is arbitrary. The police need probable cause to test you for drugs or alcohol. If your functioning is not impaired, the police have no cause to test for drugs. Similarly if your functioning is impaired but you test negative, what's the point?

Anytime you change a law, you change the incentives for self serving people (all of us) to abide by the law. We all flaunt the law and drive too fast from time to time. The reason we do this is because the punishment is not severe enough to give us an incentive to always stay below the speed limit. The reason the penalty is not higher, is because we have arrived at the point where the penalty (incentive) is sufficient to accomplish the public good. Habitual or excessive speeders pay a much higher cost than most of us occaisional or moderate speeders.

So with this in mind, what behaviour are we trying to incentive with the proposed ability of the police to test for drugs at DUI roadblocks? Are there significant numbers of drivers that are driving around high and causing accidents? If a failed road side sobriety test is sufficient in most jurisdictions for a roadside suspension, what do we hope to gain by dragging someone down to the station for a drug test. If the testing just results in more and longer prosecutions, have we gained anything? If there is no correlation between impairment and the legal limits for differnt drugs, the limits will be struck down (eventually) by the courts.

Let's see this for what it is, a bone thrown to the law and order types. If the conservatives want to do this, let them go ahead. There is little harm, but it is not going to make any real difference.