The circumstances of blind spot crashes and short- and long-term measures
SWOV has studied the circumstances of blind spot crashes and has looked for solutions and measures that can reduce the number of blind spot crashes. One of the reasons for this study was a discussion in Dutch Parliament about the blind spot issue. The design and the realization of the study were closely tuned with the Ministry of Transport. Elaborate consultations were also held with other interested parties.
The Netherlands has been struggling with the blind spot issue for many years now: serious crashes involving lorries turning right and cyclists going straight ahead. In the last decades, the European Union has introduced several measures for lorries to prevent this type of crash: in the 1980s the close proximity mirror (Class V in Directive 2003/97/EC) was made compulsory, and side underrun protection in 1995. In 2003, the Netherlands was first to introduce the wide angle mirror (Class IV in Directive 2003/97/EC); Denmark and Belgium followed a year later. This measure was specifically intended for countries with many cyclists.
The Netherlands still counts an average of 15 fatalities per year despite these measures. Although the numbers of fatalities showed a temporary considerable reduction in the years 2002 and 2003, this study shows that this was the case for all crash types involving both lorries and cyclists. This may however be due to the general attention for crashes involving lorries when the wide angle mirror was introduced, and not be caused by the mirror itself.
Each blind spot crash causes social unrest because of the severity of the crash and the notion that there must be ways to prevent this type of crash.
The study is based on analyses of serious blind spot crashes in the period 1997-2006, and on police reports from the years 2006 and 2007. The detailed crash data from the police reports were supplemented with survey data acquired from surviving cyclists and lorry drivers who had been involved in blind spot crashes. Traffic observations were also made at the locations were these crashes had occurred.
Both groups of road users were interviewed to gain insight in the way cyclists and lorry drivers deal with the blind spot problem in daily practice. In addition, the everyday traffic situation was observed and, in the cab, the lorry drivers' actual behaviour was studied.
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Blind spot crashes and their circumstances In a situation where lorries and cyclists are not separated, a blind spot crash is caused when a lorry driver turning right fails to notice a cyclist going straight on. Here the lorry driver should have given priority. The cyclist claimed his right of way, being either aware or unaware of the lorry turning right. There are three important contributing factors in this type of blind spot crash:
• (High) lorries built before 2007 make it impossible for the lorry driver to see cyclists in front of and in the right front of their cab; new lorries do offer this field of vision, but this is not or not properly made use of by lorry drivers.
• Lorry drivers fail to notice cyclists on the right side of their cab because they do not use their right mirrors properly, or because these mirrors are ill-adjusted.
• There is no code of conduct for cyclists telling them to keep out of a lorry's blind spot.
Blind spot crashes mainly happen with lorries that have had to stop at a traffic light or a main road. As long as a lorry can stay in motion, the driver seems to have a better view of the surrounding area and cyclists. After a standstill, however, he can fail to notice cyclists (after all, he also needs to keep an eye on the other traffic), and he will sometimes 'blindly' turn right due to a lack of adequate aids.
A second type of blind spot crash
Other than the 'classic' blind spot crash (lorry turning right and cyclist going straight on) described above, this study brought to light a second type of blind spot crash. These are crashes in which a lorry crosses a bicycle path (cyclists having right of way) at right angles and fails to notice a cyclist. This type of crash happens at intersections with a main road and at entering a roundabout. Crashes at these locations have become more frequent during the last few years, possibly caused by the increasing number of bicycle paths with two-way traffic and the increasing number of roundabouts. Especially cyclists who come from the right deserve attention because they are positioned in the blind spot at the right front of the lorry. A second point of attention in this type of blind spot crashes is the obstruction of the driver's view by the presence of (blind spot) mirrors on the lorry's side brackets. These limit the view, to the left as well as to the right, of both the bicycle path and the main road.
Set of four concrete measures Given the cyclists' right of way, the responsibility of avoiding a crash primarily lies with the lorry driver. However, cyclists must acknowledge their responsibility by making use of their right of way in an appropriate manner.
The following set of concrete measures offers four angles to reduce the number of blind spot crashes:
1. Separation of cyclists and lorries at locations where lorries can turn right. This separation can be realized by forcing lorries to halt at a generous distance from the halt line or the give way road marking, which places cyclists in full view in front of them. To support this motoring performance for lorry drivers, the halt lines or the give way road markings for motorized traffic are moved further backwards, at a larger distance from the intersection or roundabout.
2. A code of conduct for cyclists must be drawn up. This code will state that cyclists position themselves immediately in front of their own halt line or give way road marking and will be the first road users to depart when the light turns green or when the road is clear. The halt line or give way road marking for cyclists is closer to the intersection than that for motorized traffic. Cyclists coming from the rear must remain behind a lorry and do not position themselves beside the vehicle.
3. The introduction of measures 1 and 2 does not entirely prevent errors being committed. A check needs to be included to prevent a crash. At the location where the lorry turns off and crosses the cyclist's way, the driver needs to ascertain that the road is clear. At this point he must carry out an extra check for which he needs to make use of the front view mirror (Class VI 'front mirror' in Directive 2003/97/EC) or the front camera. This extra check needs to be made part of the driver training and the refresher courses for lorry drivers.
4. All lorries must be equipped with the new front view system. Since 2007 the front view system has been compulsory for new lorries. We recommend also making this system compulsory for lorries that were built before 2007.
Strategic solution for all types of crashes between lorries and vulnerable road users. A strategic measure to prevent blind spot crashes – and, more generally, crashes between lorries and vulnerable road users – is the elimination of possible conflicts: lorries and vulnerable road users are not at the same location (at the same time). This requires a complete, structural separation of heavy and light traffic. In the long term this can be realized by only admitting heavy freight traffic to a main road network which gives access to, for instance, distribution centres. Only light freight traffic will be allowed to use the secondary road network. The main feature that distinguishes light freight vehicles from heavy ones is the absence of the blind spot: both front and side windows provide a direct view of vulnerable road users. The SWOV publication Advancing Sustainable Safety discusses this vision in detail.
Supporting measures Supporting measures are advisable for both the set of four concrete measures and the strategic solution. The most important, ranked by stakeholder, are:
• road authorities: routing of heavy traffic in cities and the combined distribution of goods in cities;
• lorry manufacturers: development of a special type of distribution lorries with low front and side windows;
• transport companies: the introduction of safety culture and the determining of safe routes in consultation with governments and road authorities;
• lorry drivers: taking the (compulsory) refresher courses and the responsibility for well-adjusted mirrors;
• cyclists: red light discipline and acquiring the code of conduct.
Possibly effective products on the market
Using the knowledge about the circumstances of blind spot crashes, a number of products have been judged that are intended to prevent black spot crashes. One of the six products that were assessed seems an important candidate for further investigation. This is the warning system which detects cyclists with the use of, for instance, radar, and transmits a signal to the driver in his cab. However, this system needs to be adapted in such a way that the driver does not get excess information, but is only warned when it is necessary. Cyclists only need to be detected at those locations where the lorry crosses their way: the place where the driver must carry out the extra check.
SWOV recommends putting the set of four measures into execution at short notice in order to reduce the number of blind spot crashes. The supporting measures can be of assistance during the implementation.
A complete, structural separation of heavy and light traffic is the best solution to prevent conflicts between lorries and cyclists. This is one of the views of Advancing Sustainable Safety. Elaboration of this view is recommended.
SWOV also recommends further investigation of a system that detects cyclists. It concerns a warning system that for instances uses radar to inform the driver about the presence of cyclists. To limit the frequency of information signals, the possibility must be investigated of only warning the driver at the moment he needs to carry out the extra check.