that employs lane-by-lane and vehicle drive-cycle models coupled with an iterative approximation method to provide performance statistics( delay, queue length, stop rate) and estimates of capacity. The use of Highway Capacity Manual( HCM) version of SIDRA Intersection is based on the calibration of model parameters against the highway capacity manual. SIDRA Intersection allows modelling of separate Movement Classes( heavy vehicles, light vehicles, buses, bicycles, large trucks and light rail / trams) with different vehicle characteristics. These movements can be allocated to different lanes, lane segments and signal phases, for example for modelling bus priority lanes at signals.
The LOS provides a qualitative ranking of the traffic operational conditions experienced by users of a facility. The HCM defines the LOS category for freeways and multilane highway as follows: a. Free Flow Traffic. Individual users are practically unaffected by the presence of other vehicles on a road section. The choice of speeds and the manoeuvrability are free. The level of comfort is excellent as driver needs minimal attention. b. Steady traffic. The presence of other vehicles on the section begins to affect the behaviour of individual drivers. The choice of the speed is free, but the manoeuvrability has somewhat decreased. The comfort is excellent, as the driver simply needs to keep an eye on nearby vehicles. c. Steady Traffic but Limited. The presence of other vehicles affects drivers. The level of comfort is quickly decreased, and the choice of speed is affected, and manoeuvring requires vigilance. In contrast, the effect of an incident at LOS A or LOS B are minimal, and cause only minor delays in the immediate vicinity of the event d. Steady traffic at high demand. The speed and manoeuvring are severely reduced. Low level of comfort for the driver. A slight increase of the traffic risks causing some operational problems and saturating of the network. e. Traffic at saturation. Low but uniform speed. Manoeuvring is possible only under constraint of another vehicle. The user is frustrated. f. Congestion. Describes a breakdown in vehicular flow. Vehicles actually operate at low speeds in these conditions and are often required to come to a complete stop.
METHODOLOGY
In this study, there are three peak periods daily which normally occur at 7:00 to 8:00 in the morning, at 13:00 to 14:00 in the afternoon and at 17:00 to 18:00 in the evening. The traffic data was collected at the T-Intersection at Bukit Chedang Rasah Seremban on April 20, 2017( Thursday), April 21, 2017( Friday) and April 22, 2017( Saturday) using a video camera in order to record the whole movement of vehicles at the intersections. Traffic flow data was extracted from the videotapes of each intersection. All the videotapes were studied visually to extract the traffic volumes and turning movements for analysis. Every vehicle coming from all the approaches was recorded on pre-prepared data collection sheets. Hourly counts were used as input data for analysis. The studies used computer simulation to estimate emissions before and after optimisation and traffic flow data was analysed using SIDRA version 6.0.
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General parameters selection and input data decided to meet software requirements
SIDRA 6.0 running & check phasing division
Remodelling if needed
Optimisations & Re-modification
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Figure 3.1: Optimisation plan for SIDRA 6.0
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