PURPOSES : In this study, we quantitatively prove the rubber necking phenomenon for highway traffic accidents and develop a calculation model based on the influencing factors. METHODS : Vehicle detector speed data in the opposite direction to the accident point were used based on the accident data on highways over the past three years, and a comparative verification was performed between nearby vehicle detector data to verify the reliability of the data. Accordingly, a binomial logistic model, ordinal probit regression model, and multilinear regression model were developed to compare the orientation. RESULTS : There was a difference in the influencing factors based on the dependent variable, and the day of the week, vehicle type, weather, longitudinal slope, and median height had an effect. Through a regression analysis, an influence coefficient was derived to calculate the driving speed deceleration value by rubbernecking. The results of the model analysis proved that the speed reduction caused by rubbernecking was more evident during the daytime than at night, during weekends compared to weekdays, and the speed reduction was more obvious for heavy vehicles compared to other types of vehicles. It can also be concluded that longer clearance time, higher accident severity, and higher traffic volume affect traffic delay. To verify the data and model equation, the mean prediction bias (MPB) and mean absolute deviation (MAD) were calculated for hundred cases randomly extracted from the collected accident data. These results were excellent. CONCLUSIONS : It can be developed into a human-engineered model that reflects various road/facility conditions, such as highways, other lanes, general roads, and roads without a median strip. This study is meaningful as a basic study on the quantitative effect of rubber necking.

OBJECTIVES: This study aims to review a plan to reduce the shoulder width of a deformed round-trip two-lane highway with low traffic volume. METHODS: Installation of a passing lane on a round-trip two-lane (one-way one-lane) highway, and reduction of a shoulder for a round-trip four-lane highway. RESULTS : It is necessary to establish a design criterion for various highways, because the plan to reduce the lane or shoulder width of a highway with low traffic volume was analyzed to have an economic efficiency of 6.8~7.0%. CONCLUSIONS: It is necessary to seek for a plan to establish a national trunk net early by efficiently using the limited financial resources to cope with the traffic demand elastically.

The experiment was carried out during no-load condition for analysis of the relativity between MAP, hot film, oxygen, the secondary ignition and injector waveform. The experimental methods using oscilloscope were employed to measure waveform. The relativity between several waveform and the secondary waveform coming from ignition coil were measured in case of three decrepit vehicles. From these results, a summary of the important results are as follows. 1. Through fast acceleration experiments, the response time values of hot film sensor and oxygen sensor was faster than the those of the MAP sensor and oxygen sensor. 2. The values of spark line duration time was largest A, C, B type in the order named. And discharge energy of the secondary ignition waveform was largest A, B, C type 3. The value of effective discharge energy is to be nearly proportional to the spark line duration time. 4. The value of effective discharge energy directly increases as revolutions per minute increase, and the value of spark line duration time decreases as revolutions per minute increase.