The British Motorcyclists Federation, 129 Seaforth Avenue, Motspur Park, New Malden, Surrey, KT3 6JU. England. (from the UK) Telephone: 0181 942 7914 Fax: 0181 949 6215I'm sure they'll be glad to help, if they have any more details.
Enclosed:
BMF Documents
10 Mar 95
Vehicle restraints in the form of steel fences and concrete barriers, particularly those sited in central reserves of motorways and dual carriageways have been with us for some time now. Their function is to protect traffic from out of control vehicles in the opposite approaching lane by containing them or, to a lesser degree preventing vehicles from leaving the side of a road. The latest innovation which is beginning to have widespread installation is wire rope safety fence using four cables supported by steel posts and ground anchors. There appeared to have been a Department of Transport public relations campaign in progress at the moment to gain better public acceptance of WRSF. The BMF is concerned that the effects of impacts on them by motorcyclists have not been adequately compared with those of existing barriers.
Effects of Vehicle Restraints on Motorcyclists Safety Fences and Barriers have not been designed with the particular problems of motorcyclists in mind. However, studies have been undertaken in the USA, Germany and France to examine the effects of these vehicle restraints on motorcyclists and suggest improvements in design. Accident investigation by Oulet of California showed that the serious injuries suffered by motorcyclists impacting with barriers were caused by the exposed portions of posts on the Tension Corrugated Beam fencing or "Armco" to use its trade name. A shallow angle impact initially causes little injury due to the low speed component at right angles to the traffic flow and beam although the edges of the beam can cause lacerations. However, when the rider begins to tumble, the exposed tops and lower portions of the posts are encountered resultingin more direct high speed impacts. The sharp edges and corners of the posts concentrate impact forces exacerbating the potential for injury. Serious injuries involving, at least fractures of the extremities and sometimes decapitation then result. Wire mesh fencing is claimed to be more of hazardous since posts are more exposed and the top has a saw tooth edge increasing the risk of lacerations. The most motorcycle friendly vehicle restraint is one of plain concrete against which a rider will slide sustaining mainly abrasions.
The findings of Koch and Brendicke of Germany and Quincy, Vulin and Mounier of France confirmed that the primary cause of injuries was due to the posts rather than the beams. They also undertook work to reduce such injuries during impact.
The Germans devised a W-section (Sigma) post to replace standard H section posts since the former possessed fewer sharp edges. Impact attenuators made of polyethylene foam with polyurethane outer coatings and of polystyrene foam with polyurethane paint outer coatings to cover posts were developed. They also used additional beams to cover the lower portion of the posts. Tests using "post mortem remains" showed all these approaches would reduce injuries. However, German authorities were reluctant to make widespread use of them except at accident black spots on curved sections of road. Impact attenuators of the above design cost in the region of DM 30 each and in service have been shown to suffer deterioration from ultraviolet radiation. The German riders organization BVDM have developed a more voluminous impact attenuator made from expanded polystyrene in two parts which will lock together on either design of post. They cost DM 17 per post, are not subject to Ultra-Violet deterioration and, from tests, provide better protection than the composite impact attenuators.
The French concentrated on shielding the lower portions of posts with additional beams of different designs. Tests in which a dummy was launched from a sledge at 55 kph showed marked reductions in head decelerations compared with tests on impacts with barriers using unshielded posts. The height of a vehicle restraint of any construction is also an important consideration. Those used in the USA will contain cars and motorcycles but their riders can still be catapulted over them.
Since 1986, a programme to install vehicle restraints in the central reserves of all purpose trunk roads, ie those which all classes of vehicle are entitled to use, has been underway. It is now 80% complete. The Department of Transport claim that due to the effect it is having in reducing cross over accidents, it is paying for itself. The primary role of these vehicle restraints is to contain errant vehicles with the secondary function of redirecting them so that they are not deflected back into the stream of traffic.
The most common form of vehicle restraint used in Britain is Tension Corrugated Beam (TCB) fence primarily employed in central reserves and also to a lesser extent at the sides of roads for specific reasons such as to protect vehicles from a steep drop. As can be seen from the preceding section, they are not very motorcyclist friendly but have never been tested on motorcycles in the UK.
Open Box Beam is used on bridge parapets and in front of lighting installations and overhead bridge supports. In an impact it deforms less than TCB and affords better protection of whatever is behind it.
Concrete barriers are also used for this purpose as well as for generaluse in central reserves. Their design is based on the American New Jersey barrier but have more vertical sides to prevent light cars from rolling. They are likely to become more common now that they can be cast in situ by a continuous slip forming process. This means reduced installation costs with the added advantage of a being maintenance free when in use. This development will be beneficial to motorcyclists since a narrow angle collision with a featureless concrete surface is liable to cause the least injuries.
Temporary concrete barriers with interlocking sections which bolt together are also being used to protect workers during carriageway repairs but are only rated to give protection from 50 mph collisions.
A more recent innovation which is beginning to find use, is the Triton water filled barrier which is used in the same manner as the temporary prefabricated concrete barriers. This is constructed in sections of plastic which can be moved into position and locked together without the use of heavy plant. The sections are then filled with water to give the barrier its protective properties. It is claimed to be kinder to errant vehicles and fallen motorcyclists in the event of a collision having more give than the concrete version. It can also be used in place of cones in circumstances where a degree of protection is desirable.
Bushes and shrubberies are not used. 60s research demonstrated that a 20 ft thickness of dense shrubs was inadequate to restrain a car at motorway speeds. Wire Rope Safety Fence was originally developed by the Road Research Laboratory during the 1960s in two wire form and was installed on the Pennine section of the M62 in 1971. Since installation, only two motorcyclists had accidents involving this barrier in which one was uninjured and the other slightly injured. Manufactured by Bridon Ropes, this form of barrier has evolved into a four rope system with two upper and two lower steel ropes intertwined around steel posts. The full height posts at the end of each anchorage must be firmly concreted into the ground. The rest are sunk into a hard standing or installed in sockets to make replacement easier. The ends of the wire rope are anchored into the ground. Although this suggests that it should only only be used for straight sections of road, it is also used on curved sections.
Tests conducted by Bridon Ropes using cars show that WRSF is better able to contain them rather than deflecting them back into the traffic stream as TCB can. To date, accident experience has suggested that it is also able to contain heavy goods vehicles. Other claimed advantages are that the likelihood of wind blown soil and snow drifting behind it is reduced and it provides better visibility of oncoming traffic (and dazzle from their headlights). Allegedly more expensive to initially erect than TCB, WRSF is cheaper to repair. After an accident in which the posts have been knocked down, the freely hanging wire ropes can still restrain an errant vehicle. Contractors are now obliged to supply tenders for both forms of barrier are being authorized to install Wire Rope Safety Fence suggesting that it may, after all, be cheaper to install.
Current Situation Installation of WRSF is becoming increasingly widespread for motorways and trunk roads. Northern sections of the A1 M have been converted from TCB and appearances in Northamptonshire and Wiltshire have been reported. There are a number of instances of it replacing Tension Corrugated Beam.
Although it has been in use for some time at the sides of roads in remote locations, there have been recent installations to of Wire Rope Safety Fence at the side of a road in Northamptonshire where there is a greater likelihood of motorcycles impacting with it than if it were in a central reserve. However, it is legally acceptable to install vehicle restraints which have been accepted for use in central reserves at the roadside as well. It is also clearly laid down by the DoT that if there is any risk of serious injury or death from a vehicle leaving the road such as a steep drop or the presence of water, roadside restraints should be used. Objections to the Department of Transport and Highway Authorities are having little effect. The Chairman of the Motorcycle Action Group has given his approval of Wire Rope Safety Fence and copies of his letter are usually sent with replies rebuffing objections to it.
The BMF does not accept this position and regards relevant testing as essential before further installations are made. No tests of the effects of WRSF on motorcyclists have been undertaken or are intended in the UK. The DoT will not provide a position paper on the subject and merely cite a potted history of this form of barrier. The BMF considers that with its posts more exposed than those of TCB, it is liable to pose a greater danger to motorcyclists. Our contention is that comparative tests of WRSF with TCB should be conducted before the widespread installation of the former is carried out. French and German researchers have simulated impacts of motorcyclists on TCB barriers. It should be possible for the Transport Research Laboratory to devise and conduct a programme involving WRSF. The knowledge gained from crash testing of motorcycles to assess the effectiveness Leg Protectors and Air Bags is being used to create an International Standards Organization (ISO) standard. It could equally be employed in the assessment of impacts with crash barriers.
The argument that such testing is not practical or possible is not a valid one since it was regarded as impossible to devise meaningful tests and performance standards for abrasion resistance of motorcycle clothing under the PPE Directive. Both British and German researchers have independently done so in a few months.
Following a seminar in Northampton which was attended by the local council, Bridon Ropes - manufacturers of WRSF and members of the riders organizations, a rapport has been established between the BMF and Bridon Ropes. They have expressed a willingness to undertake testing on motorcycle collisions providing they are not commercially disadvantaged and other manufacturers of vehicle restraints do so as well. The use of protective impact absorbing caps on top of posts has also been discussed with them.
The Department of Transport claims that so few motorcyclists are involved in collisions with vehicle restraints positioned centrally or at the sides of roads that an expensive testing programmes is not justified. They supplied figures on motorcycle collisions with vehicle restraints in 1991. The following is a summary of accidents involving collisions with barriers and fences both at the centre and sides of roads of all types. Overall motorcycle accidents for 1991 are included to put them into proportion:
| Fatal | Serious | Slight | Total | |
| 652 | 9,097 | 31,702 | 41,451 | |
| Motorcycle collisions with restraints: | 14 | 55 | 68 | 137 |
| All vehicle collisions with restraints: | 116 | 638 | 2,616 | 3,370 |
The difficulty which motorcyclists face is that since motorcycle accidents involving central restraints are not common and at a cost of +20,000 per test in addition to the cost of constructing the fence or barrier to be tested, the DoT does not feel that any benefit from such testing will justify the costs when there are only limited sums available for this work. However, this does not lessen the BMF's concern that fences which are more dangerous to motorcyclists than those already in existence are being erected.
In the first instance, motorcyclists are recommended to make representations to their local Highway Authorities about planned or actual installations of Wire Rope Safety Fence. It is also recommended that they write to their MPs asking for the Minister responsible for roads to introduce a testing programme or, failing that to make the installation of concrete barriers more widespread, and also to convey the same arguments to the department of Transports Highways and Bridges Division.
Please write to:
Steven Norris MP Road Restraints Dept, Minister for Transport for London Local Transport & Road Safety, Highways and Bridges Division, Department of Transport 2, Marsham Street, St Christopher House, LONDON, Southwark Street, SW1P 0AATrevor Magner, BMF Government Relations Executive.
Issue 6
1st November, 1994
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