From time to time, over many years, MIRA (the Motor Industry Research Association) has carried out surveys of the handling behaviours of various classes of road vehicles. The most recent investigation has concerned modern European intercity buses, or coaches as they are termed in Britain.
The work was sponsored by the British Government together with five vehicle manufacturers who each supplied one bus. The main aim of the work was to ascertain the handling characteristics of a sample of modern buses in terms of both absolute behaviour and relative behaviour compared to other classes of road vehicles. However, the manufacturers sponsoring the work were also very interested to discover any correlation between various features of layout of the vehicles and the handling characteristics.
To quantify the vehicle behaviours, MIRA used the test and data analysis techniques it had developed with other classes of road vehicles, techniques which have been incorporatedinto ISO standard procedures.
The paper presents the more important handling characteristics of the fully laden buses, together with some typical results for other classes of road vehicles. The findings of the work may be summarised as follows:
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1.
By using “state-of-the-art” bus design it has been possible to improve the handling characteristics of heavy vehicles;
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2.
In the context of heavy vehicle behaviour, the handling characteristics of the modern buses tested are good;
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3.
It has been possible to correlate some features of bus design and layout to their handling responses.