Can heavy fines force speedsters out of the fast lane?

Published : 9:00 am  August 31, 2017 | No comments so far |  |  (85) reads | 

By Prof. Vijaya Kumar, D.Phil. (Oxon.)

Prof. Emeritus, Department of Chemistry, University of Peradeniya

Nobody, interested in seeing better discipline in our roads, can criticize the Rupees Twenty five thousand (25,000) fine which will be enforced for offences like driving under the influence of liquor or driving at excessive speeds. However, unless the prevalent mode of enforcing  fines is changed, the enhanced fines will only serve to provide more opportunities for corrupt elements in the police service.   
The breathalyzer test is based on the rapid reduction by alcohol in the presence of silver nitrate catalyst of reddish orange dichromate to green chromic ion, obtaining the level of alcohol in the exhaled air from a comparison of colours and relating it to alcohol in the blood. Since what impairs your driving isn’t the alcohol in your breath (alveolar air), but the alcohol in your blood which affects your brain, Henry’s Law is used to relate the two. At normal body temperature, 2100 ml of exhaled air is believed to have the same weight of alcohol found in 1 ml of blood. A value of 0.08% of alcohol in your blood puts you into the driving under influence category and makes you liable to a charge.   


However there are several problems in using the relationship. The 2100 ml is an average and although humans have been recorded with values as low as 1100 ml to as high as 3000 ml, most fall between 1900 and 2400 ml. A driver with a lower value is at a disadvantage in the breathalyzer test while one with the higher level has an advantage as it will show a value less than true blood alcohol level. Furthermore, a driver with fever will have a boost in alveolar alcohol (20% more if body temperature is 37oC) compared with the true blood alcohol.   

CITY-DM-12-3

The reading also depends on the proportion of red cells in blood which can vary in humans by about + 6% as this affects the amount of water in the blood. A higher value than the average 47% for males will lead to a higher breathalyzer reading, although there is an advantage for females as their average of 42% will routinely give them a lower reading. Those tested immediately after consuming liquor or even arishtas (Ayurveda medicine in liquid form) will show a higher reading. The technique used abroad is to conduct the test 15 min after being stopped. Those who hold their breath just before the test will show higher readings, while rapid inhalation/exhalation a few times before the test will give a slightly lower reading.   


Apart from these, diabetics, with uncontrolled sugar levels exhaling ketones and smokers exhaling acetaldehyde, can show higher breathalyzer values in the cheaper semiconductor based breathalyzers.   


Since the test is flawed, the option of challenging it with a blood test must be available if these high fines are introduced, although one does not know how practical it is. Another option would be to enforce the higher fines only when a breathalyzer shows blood alcohol levels of over 0.11% rather than 0.08% to adjust for the possible flaws in the method and have the existing lower fine for 0.08-0.11% levels.   

 

 

The problem with enforcing higher fines for speeding is that the absence of camera coordinated speed checks allows room for corrupt practices

 

All this assumes that breathalyzers are regularly calibrated or checked for their accuracy, unfortunately something not taken seriously in Sri Lanka. Since no work has been done, we also don’t know whether the assumptions in breathalyzer manufacture mentioned above based on Western samples is valid for a South Asian population.

  
However the best way to avoid being charged is of course to not drive after drinks. In many countries, clubs serving liquor provide a fee based driver service to take you and your vehicle home. Since many Sri Lankan have “bites” or meals after drinks they have an advantage as absorption of alcohol is slowed by food and if the post-drinking meal consumption period is about 2 hours, the alcohol consumed by most social drinkers would have reduced to acceptable level.  

 
The problem with enforcing higher fines for speeding is that the absence of camera coordinated speed checks allows room for corrupt practices. Unfortunately there are some policemen who keep a recorded high speed value on their radar gun and confront subsequent motorists (usually bus drivers) with the old readings in an effort to be paid to prevent being given a ticket. This happened to me several years ago, but not during the recent past and it would appear according to the personal experience of an election commissioner fairly prevalent even now on the A9. Camera based evidence is used abroad and heavy fines should be introduced only after such an unambiguous method is introduced. Another possibility is the use of radar guns which can provide a printout to the motorist of the speed and the time and date of occurrence and an automatic clearing of the display when the printout is removed, if such radar guns exist.   
Whatever it is, if the aim of the Government is to improve driving habits in Sri Lanka, the mere increase in fines to extremely high levels may not have the desired impact.