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Car controls for disabled drivers
be used for foot steering, including two remote steering systems, which offer alternatives to a steering wheel with additional power assistance. A fourth foot steering system is produced in Germany.
Car controls for disabled drivers Research Report 29 from the Transport and Road Research Laboratory, "Car control conversions for disabled drivers", by Christine Haslegrave (Motor Industry Research Association) presents the findings of a review of control conversions which are used by disabled drivers in Europe. The report describes the range of control equipment which is produced in the UK and elsewhere in Europe, together with the technical developments and research which are taking place. The regulations, licensing and approval processes applied to control conversions were also studied and compared for different countries. The main findings of the report relating to present and future conversions are: •
The postal survey and study tour have given an overview of the range of control types which are produced in .Europe, and have shown that several types of controls have been developed on the continent which have not been widely seen in the UK. These include System Franz foot steering, voice control, knee-operated steering and a shoulder-operated brake.
•
There are some differences in the approach to design of controls, but the types of companies and organisations carrying out conversions are very similar. The only car manufacturer contacted who was involved in the development of control conversions or in research was Regie Renault in France, although others may well increase involvement in the future.
•
Statistics on numbers of disabled drivers and converted cars are scarce and unreliable.
•
In the UK most hand-operated controls are of the 'segment' type mounted directly below the rim of the steering wheel, but on the continent rod-type brakes are more common and are m o u n t e d either below the wheel, on the facia panel or on the floor.
•
Virtually all direct brake controls have rigid mechanical linkages, but some throttle systems use cable linkages.
•
Power-assisted steering conversions are now produced with steering forces as low as 4 N at the wheel, and have recently become more readily available.
•
In the UK there are three systems commercially available which may
158 Applied Ergonomics June 1986
Most current research projects are directed at solutions to access problems, but Britain has taken a lead in recent control developments to give ultra-light steering systems~ Electronic joystick steering and hydrauli c remote control steering are both commercially available, and a hydraulic joystick steering control is being studied at the University of Birmingham. Other similar projects are also under way in Sweden and France.
•
•
Voice control and infra-red sensors have been developed using new technologies for the remote control of non-safety critical functions.
•
American controls are beginning to be introduced in some European countries, but mainly in van conversions. Their designs have a high degree of power assistance and more adjustability than is seen in European controls.
•
•
There has been very little research in Europe on the operating forces and response characteristics for controls which would be suitable for handicapped drivers, and there is currently some discussion as to whether ultra-light power-assisted steering may be too sensitive and not give adequate feedback of information to the driver. The two groups of people identified as having the greatest difficulty in being able to drive are those with neurological or psychological handicaps and those with severe weakness. Recent developments in steering systems will help the latter group, and in fact the greatest problem was perceived to be the expense of conversions.
Findings relating to approval, and licensing are: • In all countries visited, handicapped drivers take the ordinary driving test, but in every country except Britain any conversion to the vehicle is technically inspected (although in France this only applies to conversions which alter homologated systems on the car) a n d the driver is assessed to ensure that he is capable of operating the controls safely.
No country has regulations or codes of practice specifying the design or installation of the controls themselves, but Spain is intending to issue a regulation shortly. Where regulations exist, they usually prescribe modifications or types ol controls which will be reqmred for each type of disability. There is no evidence in European countries of accidents related to problems associated with control conversions, nor is there any pattern of accidents which occur to disabled drivers, and in fact from informed opinions there is some evidence that disabled drivers have fewer accidents than able-bodied drivers. Inspection pro cedures are beginning to be codified and two countries are in the process of producing guidelines for inspecticn controls. In general, procedures are flexible and concerned mostly with the suitability of the adaptation for the individual driver and with his ability to control the car. However. they often include a technical appraisal of the control installatio n and design. A few countries have instituted homologa~ion of control models. [n no country are control-operating forces specified by legislation for handicapped drivers, Laboratory car simulators are being used in assessment of driving ability, although opinions differ on whether they represent performance in road driving sufficiently accurately. There has been almost no research to date in Europe on the correlat ion between simulator tests and actual road performance. Car simulators are mainly found in assessment cent res and co nversion firms, tile most complex being those at Banstead Place Mobility (?entre in Britain and CARA in Brussels. Licensing authorities do not themselves use car simulators. "although they sometimes measure force capability in the actual car to confirm that the control operating forces are adequate, and other authorities sometimes use the results of simulator tests carried out elsewhere. Most staff who used simulators in assessing driving ability stressed that they Would not reject a potential driver solely on those tests, but would also make further trials driving actual adapted cars.
Car controls for disabled drivers Research Report 29 from the Transport and Road Research Laboratory, "Car control conversions for disabled drivers", by Christine Haslegrave (Motor Industry Research Association) presents the findings of a review of control conversions which are used by disabled drivers in Europe. The report describes the range of control equipment which is produced in the UK and elsewhere in Europe, together with the technical developments and research which are taking place. The regulations, licensing and approval processes applied to control conversions were also studied and compared for different countries. The main findings of the report relating to present and future conversions are: •
The postal survey and study tour have given an overview of the range of control types which are produced in .Europe, and have shown that several types of controls have been developed on the continent which have not been widely seen in the UK. These include System Franz foot steering, voice control, knee-operated steering and a shoulder-operated brake.
•
There are some differences in the approach to design of controls, but the types of companies and organisations carrying out conversions are very similar. The only car manufacturer contacted who was involved in the development of control conversions or in research was Regie Renault in France, although others may well increase involvement in the future.
•
Statistics on numbers of disabled drivers and converted cars are scarce and unreliable.
•
In the UK most hand-operated controls are of the 'segment' type mounted directly below the rim of the steering wheel, but on the continent rod-type brakes are more common and are m o u n t e d either below the wheel, on the facia panel or on the floor.
•
Virtually all direct brake controls have rigid mechanical linkages, but some throttle systems use cable linkages.
•
Power-assisted steering conversions are now produced with steering forces as low as 4 N at the wheel, and have recently become more readily available.
•
In the UK there are three systems commercially available which may
158 Applied Ergonomics June 1986
Most current research projects are directed at solutions to access problems, but Britain has taken a lead in recent control developments to give ultra-light steering systems~ Electronic joystick steering and hydrauli c remote control steering are both commercially available, and a hydraulic joystick steering control is being studied at the University of Birmingham. Other similar projects are also under way in Sweden and France.
•
•
Voice control and infra-red sensors have been developed using new technologies for the remote control of non-safety critical functions.
•
American controls are beginning to be introduced in some European countries, but mainly in van conversions. Their designs have a high degree of power assistance and more adjustability than is seen in European controls.
•
•
There has been very little research in Europe on the operating forces and response characteristics for controls which would be suitable for handicapped drivers, and there is currently some discussion as to whether ultra-light power-assisted steering may be too sensitive and not give adequate feedback of information to the driver. The two groups of people identified as having the greatest difficulty in being able to drive are those with neurological or psychological handicaps and those with severe weakness. Recent developments in steering systems will help the latter group, and in fact the greatest problem was perceived to be the expense of conversions.
Findings relating to approval, and licensing are: • In all countries visited, handicapped drivers take the ordinary driving test, but in every country except Britain any conversion to the vehicle is technically inspected (although in France this only applies to conversions which alter homologated systems on the car) a n d the driver is assessed to ensure that he is capable of operating the controls safely.
No country has regulations or codes of practice specifying the design or installation of the controls themselves, but Spain is intending to issue a regulation shortly. Where regulations exist, they usually prescribe modifications or types ol controls which will be reqmred for each type of disability. There is no evidence in European countries of accidents related to problems associated with control conversions, nor is there any pattern of accidents which occur to disabled drivers, and in fact from informed opinions there is some evidence that disabled drivers have fewer accidents than able-bodied drivers. Inspection pro cedures are beginning to be codified and two countries are in the process of producing guidelines for inspecticn controls. In general, procedures are flexible and concerned mostly with the suitability of the adaptation for the individual driver and with his ability to control the car. However. they often include a technical appraisal of the control installatio n and design. A few countries have instituted homologa~ion of control models. [n no country are control-operating forces specified by legislation for handicapped drivers, Laboratory car simulators are being used in assessment of driving ability, although opinions differ on whether they represent performance in road driving sufficiently accurately. There has been almost no research to date in Europe on the correlat ion between simulator tests and actual road performance. Car simulators are mainly found in assessment cent res and co nversion firms, tile most complex being those at Banstead Place Mobility (?entre in Britain and CARA in Brussels. Licensing authorities do not themselves use car simulators. "although they sometimes measure force capability in the actual car to confirm that the control operating forces are adequate, and other authorities sometimes use the results of simulator tests carried out elsewhere. Most staff who used simulators in assessing driving ability stressed that they Would not reject a potential driver solely on those tests, but would also make further trials driving actual adapted cars.