Narrow cross sections, where the narrowest (left) lane might be no more than 2.50 m wide, may present specific problems to elderly drivers. This may in particular be the case when driving on the narrow lane extends for longer periods of time, e.g., an hour. This study examined (extended) performance of a group of drivers on a narrow lane by comparing it to behaviour on present day standard lanes. The experiment was done in the TNO driving simulator. Two groups of Ss over 55 years of age drove for an hour on a narrow profile (2.50 m in the left lane) and the standard profile (3.50 m), respectively. A group of younger Ss drove on the standard lane only, thus serving as a control. For the subjects over 55, highly significant differences were found to exist between behaviour on the narrowed and on the standard profiles: TLCs were shorter, and lane exceedances more frequent and longer lasting, for the narrow cross section. Moreover, the effects were found to aggravate over a full hour of driving over the narrow profile. 1) Older drivers have no problems in the standard 3.50 profile, on which they drove as well as the younger group. 2) Older drivers do have problems in the narrow 2.50 profile, leading to a highly increased risk relative to the standard profile. 3) Performance in the narrow cross section, moreover, becomes progressively worse over the first full hour of driving. 4) 4 The impairment of performance for the elderly drivers in the narrow cross section is to be estimated as being 3 to 4 times worse overall than for younger drivers. (Author/publisher)
Abstract