Simulated safety performance of rear-end and angled vehicle interactions at isolated intersections

2009 ◽  
Vol 36 (11) ◽  
pp. 1794-1803 ◽  
Author(s):  
Flávio Cunto ◽  
Frank F. Saccomanno
Keyword(s):  
Simulation Model ◽  
Performance Measures ◽  
Safety Performance ◽  
Microscopic Simulation ◽  
Use Of Time ◽  
Intersection Safety ◽  
Potential Index ◽  
Time Specific ◽  
Isolated Intersection

This paper applies a calibrated microscopic simulation model to assess the safety implications of signalization at a stop-controlled isolated intersection. Safety performance is measured in terms of a crash potential index (CPI) that makes use of time-specific vehicle parameters, such as deceleration rates, spacing, and speed profiles. Four performance measures are obtained: (i) average CPI/vehicle, (ii) CPI 85th percentile, (iii) number of vehicles with CPI > 0 (defined as interacting), and (iv) number of conflicts (defined in terms of a given CPI threshold). Two types of interactions are considered, namely rear end and angled. For rear-end interactions, CPI/vehicle was found to be significantly higher following the introduction of fixed signal controls. For angled interactions, CPI/vehicle was found to decrease with signalization. For both types of interactions, the CPI 85th percentile was found to decrease nonlinearly with signalization, especially for higher assumed volumes on the major approach. Rear-end vehicle interactions increased significantly following signalization and with increasing volume, whereas no such increase was observed for angled interactions. The key observation is that the number of vehicles subject to angled interactions was found to decrease after signalization.

The Microscopic Simulation Based on Conflict of Pedestrian Crossing Street

2014 ◽  
Vol 505-506 ◽  
pp. 1102-1106
Author(s):  
Qi Pu ◽  
Luan Ying Sun ◽  
Cheng Gu
Keyword(s):  
Simulation Model ◽  
Weighted Average ◽  
Index Selection ◽  
Practical Application ◽  
Microscopic Simulation ◽  
Intersection Safety ◽  
Simulation Based ◽  
Risk Degree ◽  
Conflict Risk ◽  
Pedestrian Crossing

Data was gathered in order to obtain the conflict index at signal intersection when pedestrians crossed the street, and SOMK algorithm was applied to the four indexes of clustering, then index can be applied to evaluate the risk degree of signal intersection after index selection. A signal intersection was selected which was a main-secondary road intersection to simulate with VISSIM. On the basis of quantitating the pedestrian-vehicle conflict at signal intersection, calculated weighted average of the every conflict risk degree in the peak hours at the intersection, then resulted in intersection safety score of pedestrians crossing in peak hours, and evaluated safety grade according to the score. Compared and analyzed the results of actual investigation and simulation, which ensure the simulation model is effective. Afterwards the simulation can be taken into practical application based on its effectiveness.

scholarly journals Modelo para avaliação do desempenho da segurança viária através da simulação microscópica

TRANSPORTES ◽  
2010 ◽  
Vol 18 (3) ◽  
Author(s):  
Flávio José Craveiro Cunto ◽  
Frank F. Saccomanno
Keyword(s):  
Road Safety ◽  
Safety Performance ◽  
The Other ◽  
Microscopic Simulation ◽  
The Road ◽  
Potential Index ◽  
Mechanistic Approach ◽  
Proposed Model ◽  
Safety Studies ◽  
Over Time

<p><strong>Resumo: </strong>O uso da microssimulação em estudos de segurança viária tem sido investigado mais frequentemente nas últimas duas décadas.Em tese, essa ferramenta pode atuar como plataforma para o desenvolvimento de uma abordagem mais mecanística dos eventos que precedem a ocorrência de acidentes de trânsito. Este artigo apresenta um modelo para avaliação do desempenho da segurança viária através da microssimulação. O modelo utiliza o aplicativo VISSIM© versão 4.3 como plataforma de simulação e estima interações longitudinais e transversais entre veículos ao longo do tempo, a partir do índice de potencial para acidentes (CPI). A utilidade do modelo proposto foi ilustrada através de sua aplicação em interseções isoladas semaforizadas ou não. Os resultados indicam que a introdução do semáforo aumentou a frequência e severidade das interações longitudinais e, reduziu o número de veículos interagindo transversalmente. Estes resultados confirmam o potencial considerável para o uso da microssimulação em estudos de segurança viária.</p><strong>Abstract: </strong>The use of microsimulation in safety studies has been more frequently investigated over the last two decades. In theory, this tool can serve as platform for the development of a more mechanistic approach regarding the events preceding a crash. This paper presents a model for assessing the road safety performance using microsimulation. The model applies the software VISSIM© 4.3 as simulation platform and estimates rear-end and angled interactions for different vehicle over time via the crash potential index (CPI). The usefulness of the proposed model has been illustrated throughout its application to signalized and unsignalized isolated intersections. The results indicate that the signalization increased both frequency and severity for rear-end interactions, decreasing, on the other hand, the number of angled interactions. These results also confirm the potential for using microscopic simulation in road safety studies.

scholarly journals ACCESS TIME OF EMERGENCY VEHICLES UNDER THE CONDITION OF STREET BLOCKAGES AFTER A LARGE EARTHQUAKE

2016 ◽  
Vol III-4/W1 ◽  
pp. 37-44
Author(s):  
N. Hirokawa ◽  
T. Osaragi
Keyword(s):  
Simulation Model ◽  
Large Scale ◽  
Large Earthquake ◽  
Access Time ◽  
Microscopic Simulation ◽  
Property Damage ◽  
Emergency Vehicles ◽  
Fire Stations ◽  
Average Access Time ◽  
Alternative Routes

The previous studies have been carried out on accessibility in daily life. However it is an important issue to improve the accessibility of emergency vehicles after a large earthquake. In this paper, we analyzed the accessibility of firefighters by using a microscopic simulation model immediately after a large earthquake. More specifically, we constructed the simulation model, which describes the property damage, such as collapsed buildings, street blockages, outbreaks of fires, and fire spreading, and the movement of firefighters from fire stations to the locations of fires in a large-scale earthquake. Using this model, we analyzed the influence of the street-blockage on the access time of firefighters. In case streets are blocked according to property damage simulation, the result showed the average access time is more than 10 minutes in the outskirts of the 23 wards of Tokyo, and there are some firefighters arrive over 20 minutes at most. Additionally, we focused on the alternative routes and proposed that volunteers collect information on street blockages to improve the accessibility of firefighters. Finally we demonstrated that access time of firefighters can be reduced to the same level as the case no streets were blocked if 0.3% of residents collected information in 10 minutes.

Simulation and ABC to Improve the Performance of Emergency Department

2012 ◽  
Vol 3 (3) ◽  
pp. 15-31
Author(s):  
Abbas Al-Refaie ◽  
Mohammed Shurrab ◽  
Ming-Hsien Li
Keyword(s):  
Emergency Department ◽  
Simulation Model ◽  
Performance Measures ◽  
Decision Makers ◽  
Activity Based Costing ◽  
Cost Information ◽  
Controllable Factors ◽  
Financial Practices

This study aims at developing an Activity Based Costing (ABC) for the Emergency Department (ED) in a Jordanian hospital to determine associated costs and clarifies the financial practices inside ED rooms. For this purpose, simulation model is built for patients at the current ED activities and determine the costs for each room in ED. The total costs (JD), number of served patients, and profits (JD) are 263562, 10256, and 146677, respectively. Improvement is suggested by studying three three-level controllable factors using simulation. It is noted that focusing on the lowest total costs, B-1 (adding two beds with one added nurse) and B-2 (introducing four beds with two added nurses) provide the two smallest total costs (JD) of 252568 and 253320, respectively. Whereas, for the largest number of served patients is achieved by A-1 (assigning one sharing doctor for Abdominal) and C-1 (adding another room for abdominal with new doctor) of equal number of served patients of 10466. In order to combine these two performance measures, the profit associated with each scenario is considered. It is found that factor A-1 provides the largest profit (= 150,390 JD). The results of this research may provide decision makers valuable cost information that helps them in improving ED performance.

Generating Driver Population for the Microscopic Simulation Model (CORSIM)

SIMULATION ◽  
2001 ◽  
Vol 76 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Steven I.-Jy Chien ◽  
Kyriacos C. Mouskos ◽  
Shoaib M. Chowdhury
Keyword(s):  
Simulation Model ◽  
Microscopic Simulation

scholarly journals EVALUATION OF BUS PRIORITY SYSTEM WITH MICROSCOPIC SIMULATION MODEL

2006 ◽  
Vol 23 ◽  
pp. 945-953 ◽  
Author(s):  
Madhu ERRAMPALLI ◽  
Masashi OKUSHIMA ◽  
Takamasa AKIYAMA
Keyword(s):  
Simulation Model ◽  
Microscopic Simulation ◽  
Bus Priority ◽  
Priority System
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