Lane Reduction and Queue Length Relationship on Arterial and Collector Roads

Geometric diversity of roads for an example is the narrowing of road segments. The purpose of this research is to determine whether lane reduction leads to significant queue lengths, observe the behaviour of drivers on those road segments, and compare the actual queue length to the queue length generated by PTV Vissim. The data used in this study consists of direct observations during peak hours in the morning, afternoon, and evening, along with simulations using PTV Vissim. The queue results obtained from PTV Vissim were validated using two types of tests. The research findings indicate a significant relationship between queue length and lane reduction during peak hours on workdays. However, during the evening peak hours on weekends, the queue length is not significantly affected by lane reduction. As a potential solution, widening each road segment in PTV Vissim was tested, which increased road capacity and slightly reduced the queues that occurred.


Introduction
The problems that occur in DKI Jakarta are more than just the dense population and various kinds of social problems.There are also transportation problems that arise due to the growth of vehicles which increase every year and are out of control.According to data from BPS, the annual growth of vehicles in DKI Jakarta is 4.3%.This is exacerbated by the problem of road geometric non-uniformity.Road geometric non-uniformity, for example, narrowing of roads.Narrowing of road is a condition where the previous traffic capacity (upstream) is greater than the entry path (downstream), resulting in a change in vehicle travel from free flow to being hampered and resulting in a reduction in speed and increased density between vehicles [1].Narrowing of roads results in delays and queues [2].According to MKJI 1997, delay is the travel time required by an object to go through an intersection compared to conditions without an intersection while queues are the number of vehicles queuing in an intersection approach and defined in vehicles or passenger car units.
A case study on Suryanata road at Samarinda City mention that there are several important parameters that affect lane reduction including the road width, the length of the lane narrowing area and the traffic volume [3].In this study an alternative simulation was carried out by redesigning the area where there was a reduction in lanes by extending the narrowing area from 12 to 22 meters using the trial-error method.Other research on evaluating driver behaviour in lane reduction areas has concluded that it is advisable to change lanes 100 m before narrowing to increase traffic efficiency [4].Based on that previous research, this study will continue to analyse the relationship between lane reduction and queue length and trying to solve this queuing problem using Vissim Simulation with widening the road even though it is only 1 or 2 meters depend on availability of space.

Literature Study
Roads are land transportation infrastructure covering all road segments, including auxiliary buildings and equipment intended for traffic, which are at ground level, above ground level, below ground or water level, as well as above water level, except railroads, roads, lorries, and cable roads.One form of road geometric diversity is lane narrowing.Lane narrowing is a type of single braid [5].
The degree of saturation will indicate the density of a road segment with a variation value between zero and one [6].If the degree of saturation value is zero, it indicates that the traffic conditions are quiet, where vehicles on one road do not affect each other, but if the degree of saturation value is close to one, then it indicates that the traffic conditions on the road are congested, where the presence of vehicles on one road section will affect one another.The level of road service is one of the aspects in measuring road performance parameters [5].The level of road service is related to the degree of saturation, where the value of the degree of saturation will determine the level of road service.

Result and Discussion
Below is geometric condition data at the review location which can be seen in Figure 1 for the location of Jl.Asia Afrika (5 lanes to 4 lanes), Figure 2 for Jl.Gerbang Pemuda (4 to 3), Figure 3 for Jl.Joglo Raya (3 to 2) and Figure 4 for Jl.Terogong Raya (2 to 1).

Vehicle Volume
The volume of vehicles that were collected at each location included three types of vehicles, namely Motorcycles (MC), Light Vehicles (LV), and Heavy Vehicles (HV).At each location, data collected during the morning, afternoon and evening peak hours on weekday and weekend conditions based on the results of the preliminary survey that was previously conducted.Vehicles passing through the surveyed road sections will be counted and converted into passenger car units (pcu) with the conversion values for vehicles MC 0.5, LV 1.0, and HV 1.3.As an illustration, Figure 5 shows the fluctuation in volume on weekday conditions on the Jl.Terogong Raya (2 to 1).

Vehicle Queue Length
Vehicle queues are found using a wheel meter tool with the zero point on the stopped vehicle until the end of the queue of vehicles.Figure 6 shows a graph of the length of the queue that occurs on the Jl.Terogong Raya section (2 to 1) during weekday.The graph shows the fluctuation in the queue length due to the vehicle volume on 2 to 1 road segment.The queue appears when the degree of saturation value of 1.

Capacity
Table 1 is a table containing the capacity of each road section of one lane.Based on Table 1, it is normal that Jl.Asia Afrika section (5 to 4) become higher capacity because of the number of lanes.Please consider that this capacity will be an important parameter for the queueing.

Degree of Saturation (DS)
Table 2 shows DS at morning peak hours during weekdays with all DS are more than 0.8 which can be said in unstable traffic conditions.In 4 to 3 conditions, the degree saturation reach 1.13 because the vehicle volume larger than the road capacity and, in that condition, appear long queue.

Travel Speed
Travel speed is the speed required by the driver when passing through the narrowing of the road based on MKJI 1997.Table 3 shows the result of average travel speed needed to pass through the narrowing segment of the road in the morning peak hour during weekdays.As shown in Table 3, it was found that at 3 to 2 lane road condition the travel speed is zero, which is caused by the saturation degree reaching its peak value.Consequently, the travel speed on this road segment decrease to 0.

Queue Length Relationship Analysis with one lane reduction
This study aims to investigate the relationship between queue length and lane reduction in three different peak traffic conditions.The traffic conditions during weekdays vary during the morning, afternoon, and evening peak hours, and are influenced by factors such as vehicle volume and degree of saturation (DS).
High DS can lead to vehicle queues on road segments that experience lane reduction.Figure 7 to 9 show the result for the graphic correlation on weekdays during the morning, afternoon, and evening peak hours.As Shown in Figure 7, at morning peak hours the queue length is significantly affected by the lane reduction.Based on the results there is no significant relationship between queue length and lane reduction at 5 to 4 and 4 to 3.This phenomenon can be explained by the fact that the queue becomes reduced due to an adequate number of lanes to accommodate vehicles waiting in line.However, for lanes 3 to 2 and 2 to 1, the length of the queue becomes crucial due to the insufficient number of lanes that can be passed through.

PTV Vissim Calibration
To obtain optimal results on narrow roads, an analysis was carried out using PTV Vissim software.The analysis was carried out by modelling traffic on the roads and comparing survey data with data generated by PTV Vissim software.The purpose of this analysis is to determine to what extent the survey data match the data generated by the software and to evaluate possible traffic alternatives on that road section.
To get a simulation that can reflect the conditions of driver behaviour in Indonesia on the PTV Vissim software, modifications are made to the driving behaviour parameters, because driver behaviour in driving can certainly result in different traffic conditions.Table 4 shows the settings for driving behaviour.The Driving Behaviour calibration value are from Research that been done in 2021 [7]  shows the validation results for modelling simulations in several locations where there is a reduction of 1 lane on Weekday conditions.Based on the results shown in Table 9.The volume output from the modelling simulation is acceptable because the GEH test results are within the standard criteria (GEH < 5).

PTV Vissim Simulation for Solution
The solutions are carried out according to improve the capacity of the roads by consider the conditions and limitations of the available space in each road.Table 6 shows the results of the maximum road widening to each road and compare the volume and queuing length.Based on the results of Table 6, on the Jl.Asia Africa (5 to 4), there is no reducing on queue length.when widening each lane from 3.3 to 3.5.On the Jl.Gerbang Pemuda (4 to 3), the queue length reduces 17.6% after widening each lane from 3.1 m to 3.5 m.On the Jl.Joglo Raya (3 to 2), the queue length reduced below 1% after widening each lane from 3.3 m to 3.5 and on the Jl.Terogong Raya (2 to 1), the queue length reduces 5.4% after widening each lane from 3.75 m to 3.9m.On the volume aspect, the widening of the lane has no significant volume increase as well.

Conclusion
In certain conditions such as peak traffic such as in the morning on weekdays, the reduction of lanes has a significant effect on the length of queues that occur on road sections that experience geometric unevenness of the road.The length of the queue is also influenced by the degree of saturation value.A

Figure 7 .Figure 8 . 6 Figure 9 .
Figure 7. Queue Length Relationship Analysis for lane reduction on Weekday in the morning peak hour

Table 1 .
Calculation Results of Road Section Capacity

Table 2 .
Degree of Saturation for Each Road

Table 3 .
The Average Travel Speed on Each Road

Table 4 .
Calibration Settings for Driving Behaviour After conducting modelling simulations at each lane narrowing location, PTV Vissim software will obtain results in the form of queue length values and simulation output volumes.To validate the simulation results from PTV Vissim, the output results were validated using the GEH Test.Tables5

Table 5 .
Volume Validation Test