| Abstract [eng] |
The purpose of this investigation is to determine limit parameters of the transport flows movement, which define permeability limits of the transport connections. So, the object of this investigation was Islandijos road (directions of Vilnius and Klaipėda). In the research it was modeled the situation, how the permeability of the road decreases, when section of the street narrows from two to one lane, with the simulated traffic accident. The experimental investigation data was recorded at the midday and the evening time, using the selected average of the day (day time 12:00 – 13:00 hours, evening time 17:00 – 18:00 hours). The speed of the transport flows movement was also recorded. Recorded data was used for the measurements of the limit parameters (traffic density and intensity) and modeling of traffic during the accident. Experimental investigation has shown, that 80 % of the traffic flow consists of cars. During analytical investigation, the limit parameters were calculated for the simple transport flow (trucks were converted to cars using special ratio). Due to special ratios the dynamic size of car was evaluated. Using dynamic size value, the limit parameters were determined at the appropriate speed. Situation was modeled with simulated traffic accident and it was determined how the traffic flow movement changes. In the evening, when traffic intensity is increased (usually heavier than in the daytime), traffic jam builds up, which can be from 4,7 km to 8,3 km, according to the modeling results. This traffic jam would spread in about 49 and 90 minutes. In such situations, the traffic jam makes influence even for the streets around. The such kind of accident was happened in February 1st, about 5 o’clock in the evening. 4 vehicles has collided (1 truck and 3 cars) near the shopping mall “MEGA”. The traffic jam was about 5,6 km length, it reached even Savanorių avenue, but the right length of the traffic jam is unknown. The traffic jam spread in about 2 hours. |
