This protocol describes the process of solving a microscopic traffic problem with simulation. The whole process contains a detailed description of data collection, data analysis, simulation model build, simulation calibration, and sensitive analysis. Modifications and troubleshooting of the method are also discussed.
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Method Article
Evaluation of an Exclusive Spur Dike U-Turn Design with Radar-Collected Data and Simulation
In This Article
Summary
Abstract
Traditional U-turn designs can improve operational features obviously, while U-turn diversions and merge segments still cause traffic congestion, conflicts, and delays. An exclusive spur dike U-turn lane design (ESUL) is proposed here to solve the disadvantages of traditional U-turn designs. To evaluate the operation performance of ESUL, a traffic simulation protocol is needed. The whole simulation process includes five steps: data collection, data analysis, simulation model build, simulation calibration, and sensitive analysis. Data collection and simulation model build are two critical steps and are described later in greater detail. Three indexes (travel time, delay, and number of stops) are commonly used in the evaluation, and other parameters can be measured from the simulation according to experimental needs. The results show that the ESUL significantly diminishes the disadvantages of traditional U-turn designs. The simulation can be applied to solve microscopic traffic problems, such as in single or several adjacent intersections or short segments. This method is not suitable for larger scale road networks or evaluations without data collection.
Introduction
Some traffic problems, such as traffic congestion at an intersection or short segment, can be solved or improved by optimizing the road design, change signal timing, traffic management measurements, and other transportation technologies1,2,3,4. These improvements either have a positive or negative effect on traffic flow operations compared to the original situations. The changes in traffic operations can be compared in traffic simulation software rather than in actual reconstruction of the intersection or segment. The traffic simulation meth....
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Protocol
1. Preparation of the equipment
- Prepare two of each of the following devices to collect two-direction traffic flows: radars, laptops, batteries and cables for radars and laptops, cameras, and radar and camera tripods.
NOTE: The radar and its corresponding software are used to collect vehicle speed and trajectory, and this is more accurate than a speed gun. The radar is not the only choice if other equipment is available for collecting vehicle speed, trajectory, and volume. As radar signals can be easily blocked by large vehicles, videos shot by cameras can be used for vehicle counting. During the investigation, if the weather is rainy or sunny, protec....
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Results
Figure 2 shows the illustration of the ESUL for U-turn median opening. WENS mean four cardinal directions. The main road has six lanes with two directions. Greenbelts divide non-motorized lane on both sides and divide the two directions in the middle. Flow 1 is the east to west through traffic, flow 2 is east to east U-turn flow, flow 3 is west to east through traffic, and flow 4 is west to west U-turn traffic.
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Discussion
In this article, the procedure of solving a traffic problem at an intersection or short segment using simulation was discussed. Several points deserve special attention and are discussed in more detail here.
Field data collection is the first thing deserving attention. Some requirements for data collection location are as follows: 1) Finding a suitable location for data collection. The location should be similar to the road geometric shape in the study, which is the premise of data collection........
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Disclosures
The authors have nothing to disclose.
Acknowledgements
The authors would like to acknowledge the China Scholarship Council for partially funding this work was with the file No. 201506560015.
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Materials
| Name | Company | Catalog Number | Comments |
|---|---|---|---|
| Battery | Beijing Aozeer Technology Company | LPB-568S | Capacity: 3.7v/50000mAh. Two ports, DC 1 out:19v/5A (max), for one laptop. DC 2 out:12v/3A (max), for one radar. |
| Battery Cable | Beijing Aozeer Technology Company | No Catalog Number | Connect one battery with one laptop. |
| Camera | SONY | a6000/as50r | The videos shot by the cameras were 1080p, which means the resolution is 1920*1080. |
| Camera Tripod | WEI FENG | 3560/3130 | The camera tripod height is 1.4m. |
| Laptop | Dell | C2H2L82 | Operate Windows 7 basic system. |
| Matlab Software | MathWorks | R2016a | |
| Radar | Beijing Aozeer Technology Company | SD/D CADX-0037 | |
| Radar Software | Beijing Aozeer Technology Company | Datalogger | |
| Radar Tripod | Beijing Aozeer Technology Company | No Catalog Number | Corresponding tripods which could connect with radars, the height is 2m at most. |
| Reflective Vest | Customized | No Catalog Number | |
| VISSIM Software | PTV AG group | PTV vissim 10.00-07 student version |
References
- Tang, J. Q., Heinimann, H. R., Ma, X. L. A resilience-oriented approach for quantitatively assessing recurrent spatial-temporal congestion on urban roads. PLoS ONE. 13 (1), e0190616(2018).
- Bared, J. G., Kaisar, E. I. Me....
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