THE CORRELATION BETWEEN LANE WIDTH AND DRIVERS BEHAVIOR WHO USE THE OPPOSITE LANE RELATED TO TRAFFIC ACCIDENTS
Determining a lane width must consider the road function and the road class, because lane width of a roadway greatly influences of safety and comfort of driving, for two lanes undivided roadway with have narrow lanes as well as narrow shoulders, the risk of severe lane-departure crashes increases. Drivers may shift even closer to the road centerline as they become less comfortable to meet oncoming traffic. Meanwhile, drivers may shift closer to the shoulder edge and are at greater risk of driving off the paved portion of the roadway. On the other hand, drivers’ behavior in almost urban area in Indonesia not follows the queuing theory; they usually drive with cross lane maneuver, crossing from one lane to another lane, not straight in one lane continuously. Moreover, this behavior is worst for the motor cycle user, whereas motor cycle was dominating of traffic volume in Indonesia. Thus, we assume that there a potential of road accidents because the drivers maneuvers behavior. The research conducted in four roads in urban area in different cities in Sumatra Island. Remote camera equipment was installed to capture motorist behavior; we divided each lane into three positions, plus one position in opposite lane. The analysis is to measure the road capacity, degree of saturation and density, and the correlation with drivers who use the opposite lane. The result indicated that in flow of mixed vehicle 1.16% of drivers use the opposite lane. Furthermore, 50.81% drivers choose driving in the next of road centerline. Video recording result shows, there are significant enough of correlation between Density and drivers who use the opposite lane with R² = 0.573. Also similar correlation between Degree of Saturation and drivers who use the opposite lane with R² = 0.535. Meanwhile, for correlation between volume and the drivers who use the opposite lane not too significant with R² = 0.358. This article contributes understanding of the natural riding style of cars and motor cycle user and proposes recommendations for future research that would support investment in the design of lane width.