• Journal of Korean Society of Transportation
• /
• v.26 no.6
• /
• pp.71-80
• /
• 2008

Typically uncontrolled intersections are characterized by the absence of signal, stop and yield sign, and by very light traffic volume. In this study, a gap acceptance model for such uncontrolled intersections has been modeled. The motivation is to identify the behavior of drivers so that the traffic flow phenomena can be easily understood. For this, actual traffic survey was accomplished at intersections in Suwon and the data have been fed into modeling process. The logit model was used and the results showed that total delay experienced by drivers, turning right movement, age, sex, and the existence of passenger affected gap acceptance. For example, male drivers, with experiencing longer delay and having passenger(s) with them, accepted shorter gaps. These identified characteristics regarding gap acceptance could be used for facility design and/or safety oriented traffic information dissemination near uncontrolled intersections.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.17 no.1
• /
• pp.42-54
• /
• 2018

This study is to establish the traffic volume-based warrants of left-turn lanes in unsignalized intersections based on a risk probability methodology. This study applied a risk probability of a potential rear-end collision between a left-turn vehicle and the immediately following through vehicle. With the shifted negative exponential model and the compound probability theorem, the risk probability can be expressed as the function of directional volumes, opposing volumes and the percentage of left-turns for a two-lane and four-land highway, respectively. The warrants of installing left-turn lanes on unsignalized intersections were developed with the risk probability. The warrants define the total approaching and opposing volumes to encourage a left-turn lane as a function of operating speed, percentage of left-turn, and number of lanes.

• Journal of Korean Society of Transportation
• /
• v.19 no.5
• /
• pp.109-117
• /
• 2001

The median encroachment accident model proposed in this paper is the first step to develop cost-effective criteria about installing facilities preventing traffic accidents by median encroachment. This model consists of expected annual number of median encroachment on roadway and conditional probability to collide with vehicles on opposite lane after encroachment. Expected encroachment number is related to traffic volume and quote from a study of Hutchinson & Kennedy(1966). The probability of vehicle collision is composed of assumed headway distribution of opposite directional vehicles (negative exponential distribution), driving time of encroaching vehicle and Gap & Gap acceptance model. By using expected accident number yielded from the presented model, it will be able to calculate the benefit of reduced accident and to analyze the cost of installing facilities. Therefore this will help develop cost-effective criteria of what, to install in the median.