Biomedical subjects

D Mahalel

Publications and source records attributed to D Mahalel.

3 recordsLinked to original sources

PubMed1986

Safety improvements and driver perception.

The paper deals with potential influences of engineering standards on driver perception. The argument is advanced that, in certain cases, the common belief that simplification of the driving task increases safety might be misleading. This might be the situation following engineering improvements. Driver confidence in the system may then be increased and driving task difficulties may be underestimated. As a result, decision criteria will be biased and driver attention level decreased. The overall effect is a degradation in driver performance which is due to a poorer detection of relevant cues and to poorer criteria. This degradation ultimately leads to an increase in accidents. The challenge of road engineering, therefore, should be to find the optimal balance between environmental demands (e.g. engineering standards and design levels) and drivers' perception of task difficulties.

Automobile Driving↗

PubMed1985

Safety evaluation of flashing amber operation at signalized intersections.

The safety of a flashing amber signal for all directions at off-peak hours as a replacement for regular traffic signal operations was evaluated. The proposed control strategy was motivated by the need for energy conservation through reduced amounts of acceleration and of idling time of vehicles. The methodology of the study employed as a measure a broadened definition of "conflict" that freed observers from the need to detect only emergency evasive manoeuvres and decreased their subjective interpretations. Observations were carried out by trained observers at a sample of intersections, using two control strategies: full signal operation and flashing amber phase. Stationed at each leg of an intersection, the observers noted the travel direction of any two vehicles involved in a conflict. The results showed that the most frequent type of conflict under full signal operation was of the rear-end type; during the flashing amber operation, crossing and merging conflicts were dominant. It was concluded that up to a volume of 600 vehicles per hour, flashing operation does not increase the number of conflicts.

Accidents, Traffic↗

PubMed1985

Driver's decision process on termination of the green light.

The paper describes the background and evaluates the effectiveness of a flashing green phase just before the amber leading to red phase in the traffic signal cycle. This type of signal sequence, practiced in Israel and a few other countries, was thought to provide drivers with useful information which should lead to better stop or go decisions. However, accident analysis studies have shown an increase in collisions following the introduction of a flashing green. A laboratory simulation study designed to explain the accident findings was conducted. It was found that the flashing green elicited from the drivers an earlier decision response and a higher number of inappropriate stopping decisions, particularly close to the intersection. The pattern of stopping and crossing decisions in the flashing green program suggests more friction between stopping and nonstopping vehicles and, therefore, a higher likelihood of front-rear collisions compared to a regular program.

Accidents, Traffic↗