The study dealt with a proposed taper length formula that yields shorter tapers at design speeds below 60 mph than the existing formula, L=WS. Speed, erratic manoeuvres, conflicts and encroachment data were collected at four sites, day and night, covering a variety of design speeds and taper lengths. The analyses of the collected data do not implicate the proposed taper lengths as being more hazardous. Erratic-manoeuvre and slow-moving conflicts rates were never greater with the proposed taper than with the standard or existing taper. There was no indication that the proposed taper lengths resulted in a greater number of passenger vehicle or truck encroachments on adjacent lanes. (Author/publisher)
Abstract