ENTEVISTADOR: ANDREA CARDENAS L: LEONARDO

Detection of non-seat belt wearers is generally regarded as one of the most difficult aspects of seat belt enforcement. Police surveys have indicated that the difficulties associated with the detection of seat belt violations may be the one of the main problems hindering the effective enforcement of seat belt laws (Yann et al., 1993). It is the inconspicuous nature of the offence which makes detection difficult. The problem is that seat belt violations do not occur at particular times or locations and are not associated with a certain type of driving behaviour. Although, the police maintain that their 'eyes' have been well trained to observe seat belt violations, there are no overt signs such as speed or poor or dangerous driving. Yann et al, (1993) have identified a number of factors which contribute to the difficulty in detection of seat belt violations.

• Seat belt wearing is one of a number of offences that require police observation on the road, and the police are not able to check everything, all of the time, while still maintaining concentration on their own safety while driving;

• The speed at which vehicles travel, particularly on highways, makes detection difficult and the problem is heightened by occupants wearing dark clothing or being located in the rear seating positions, and by vehicles with tinted windows and travelling at night; • Detecting non-compliance of occupants of vehicles travelling in the opposite direction

to the police vehicle is also very difficult, not to mention the difficulty and danger involved in turning around and pursuing the offender.

• The police usually have to be close to a vehicle to see whether the occupant is wearing a seat belt or not and this allows the road user to quickly put the seat belt on, when they see a police vehicle, well before a police officer can visually detect an offence. • In situations where the majority of road users comply with the law, detection is

difficult because the chance of detecting a non-seat belt wearer is quite low, and the police may therefore devote less time to what they perceive as a low probability detection event.

Detection of seat belt offences is dependent upon the police being able to clearly observe occupants in a vehicle. This requires the police to be located sufficiently close to a vehicle to be absolutely certain that a seat belt violation is being committed. A number of factors including the speed of the vehicle, traffic density, the location of the vehicle in the traffic stream and the location of the actual police unit can make detection very difficult. These factors have a number of implications for the type of policing operations that can be used to detect offending motorists.

Stationary enforcement

Stationary policing operations are often employed as a means of enforcing seat belt laws (Australian Automobile Association, 1986). The only problem with this type of enforcement technique is that it usually requires the police to be located sufficiently close to a vehicle that seat belt wearing behaviour can be observed. This requirement may lead to difficulties in high volume, high speed traffic situations because when an offence is detected the driver has to be notified and given time to stop by the side of the roadway. There are two possible solutions to this problem. Firstly, enforcement operations can be undertaken at traffic slow points such as at intersections and roadway entry locations. This approach has the benefit that such enforcement operations are highly visible and it encourages road users to adopt appropriate seat belt wearing behaviour (Leivesley, 1987). However, the disadvantage is that road users usually have enough time to put on their seat belt and as a result apprehension rates are quite low.

The second, most often used approach is to employ two police units, along a stretch of roadway, a short distance apart from one another (Australian Automobile Association, 1986). The first police unit is assigned the task of detecting offenders and then conveying the information to the second police unit which is responsible for stopping offenders and issuing an infringement notice. The main problem with this approach is that it can be extremely resource intensive and only a small number of offenders can be processed at any one time.

Mobile enforcement

Mobile policing operations to enforce seat belt usage are usually undertaken in association with routine policing patrols. If the police, during the course of general traffic enforcement operations, observe a vehicle occupant not wearing a seat belt then the vehicle is stopped and an infringement notice issued (Leivesley, 1987). The benefit of mobile enforcement operations is that the occupant has less time to put on the seat belt and the added manoeuvrability of the police vehicle makes detection and apprehension easier.

The use of police motorcycles has been identified (Yann et al., 1993) as a particular form of mobile enforcement that can increase the overall effectiveness of seat belt surveillance operations. Motorcycles are more manoeuvrable than other types of police vehicles and are not only able to turn and chase an offender more quickly but can also be positioned so as to provide a better view into vehicles. The only problem associated with this type of seat belt enforcement strategy is that there are only limited numbers of motorbikes available to the police.

Automated seat belt enforcement

The difficulties associated with traditional methods of detection of seat belt violations have led a number of researchers to discuss the possible use of automated detection devices. Lock (1993) has suggested that the images obtained during automated speed enforcement operations could also be used as a means of detecting seat belt violations. He indicated that high quality digital images can, in many cases, clearly show whether or not occupants are wearing seat belts. He further added that, in most countries, images are already manually processed and asking operators to include a check for seat belt violations would not place a significant additional burden on policing resources.

The use of automated detection devices as a means of enforcing seat belt laws has a number of benefits. Firstly, it negates the requirement to undertake specific seat belt enforcement operations and increases the resources available to the police for other activities. Secondly, the knowledge that seat belt usage was being enforced using automated detection devices would increase the perceived risk of detection and may result in higher usage rates. This type of enforcement technique would be most effective in countries where seat belt laws are not actively enforced due to limited policing resources and doubts exist about the effectiveness and necessity of undertaking traditional seat belt enforcement operations.

The use of information, gathered as a result of a speed offence, to prosecute non-seat belt wearers may be perceived as being a questionable enforcement practice because it targets only one particular type of road user. However, linking seat belt usage to speeding behaviour may have a number of benefits. Firstly, it has been shown that drivers who do not to use seat belts are more likely to have commit other traffic offences, such as speeding (Hunter et al., 1988; Fockler & Cooper, 1988), and targeting this group of drivers may therefore result in the greatest injury reduction potential. Secondly, seat belt effectiveness is directly related to speeding behaviour because the higher the accident speed the greater the reliance placed on occupant restraint devices to reduce injury severity.