scholarly journals Safety evaluation of left-turn priority phasing at Toronto intersections

2021 ◽  
Author(s):  
Anwarul Haq Dogar
Keyword(s):  
Traffic Safety ◽  
Traffic Accidents ◽  
Safety Evaluation ◽  
Vital Role ◽  
Signalized Intersections ◽  
Side Impact ◽  
Empirical Bayesian ◽  
Left Turn ◽  
Safety Performance Functions ◽  
The City

Traffic accidents cause a huge loss to the society. According to statistics, 50% of all accidents occur at urban intersections and 47% of these are due to left-turn collisions. Countermeasure Implementation at these locations therefore can play a vital role in the improvement of traffic safety. This study illustrates a methodology for evaluation of urban 4-legged signalized intersections treated with left-turn priority phasing. The methodology is applied to three important collisions types: those due to left-turn collisions; those due to left-turn side impact collisions; and all impact types combined collisions. Data used in this analysis were obtained from the City of Toronto. Safety Performance Functions for left-turn and all impact types combined collisions which were developed by the City of Toronto, were calibrated and used in an empirical Bayesian methodology that was employed to estimate the expected frequency of accidents occurring at each intersection in order to evaluate the effectiveness of left-turn priority phasing in reducing this frequency. The results revealed that left-turn priority phasing can be an effective treatment for addressing and reducing the number of collision at signalized intersections. Flashing advance green phasing is more effective in improving safety for two of three types; all left-turn and all impact types combined collisions. Left-turn green arrow (protected/permissive) phasing is more effective for left-turn side impact collisions. By implementing this type of treatment, the number of crashes and the associated monetary loss to society could be significantly reduced.

scholarly journals Safety evaluation of left-turn priority phasing at Toronto intersections

2021 ◽  
Author(s):  
Anwarul Haq Dogar
Keyword(s):  
Traffic Safety ◽  
Traffic Accidents ◽  
Safety Evaluation ◽  
Vital Role ◽  
Signalized Intersections ◽  
Side Impact ◽  
Empirical Bayesian ◽  
Left Turn ◽  
Safety Performance Functions ◽  
The City

Traffic accidents cause a huge loss to the society. According to statistics, 50% of all accidents occur at urban intersections and 47% of these are due to left-turn collisions. Countermeasure Implementation at these locations therefore can play a vital role in the improvement of traffic safety. This study illustrates a methodology for evaluation of urban 4-legged signalized intersections treated with left-turn priority phasing. The methodology is applied to three important collisions types: those due to left-turn collisions; those due to left-turn side impact collisions; and all impact types combined collisions. Data used in this analysis were obtained from the City of Toronto. Safety Performance Functions for left-turn and all impact types combined collisions which were developed by the City of Toronto, were calibrated and used in an empirical Bayesian methodology that was employed to estimate the expected frequency of accidents occurring at each intersection in order to evaluate the effectiveness of left-turn priority phasing in reducing this frequency. The results revealed that left-turn priority phasing can be an effective treatment for addressing and reducing the number of collision at signalized intersections. Flashing advance green phasing is more effective in improving safety for two of three types; all left-turn and all impact types combined collisions. Left-turn green arrow (protected/permissive) phasing is more effective for left-turn side impact collisions. By implementing this type of treatment, the number of crashes and the associated monetary loss to society could be significantly reduced.

scholarly journals PENENTUAN BIAYA KECELAKAAN LALU LINTAS: STUDI KASUS LOMBOK TIMUR

2018 ◽  
Vol 1 (3) ◽  
pp. 128
Author(s):  
Andyka Kusuma ◽  
Tri Tjahjono ◽  
Nuzul Achjar
Keyword(s):  
Traffic Safety ◽  
Human Development Index ◽  
Traffic Accident ◽  
Analytical Approach ◽  
Traffic Accidents ◽  
Price Index ◽  
Consumer Price Index ◽  
Potential Losses ◽  
The Cost ◽  
The City

Traffic accident cost analysis is needed to predict potential losses of nation due to the emergence of traffic accident victims. The cost of traffic accidents in Indonesia is based on the characteristics of the City of Bandung in 2003, and it is shown that the cost of traffic accidents can vary according to regional characteristics. This study tries to compare the analytical approach in Bandung in 2003 with the Consumer Price Index and Human Development Index approaches for an area with medium accessibility, namely East Lombok, West Nusa Tenggara Province. The location of traffic accidents greatly influences the cost of traffic accidents, because the costs on inter-city roads are relatively higher compared to those on roads in the city. This study shows that the cost of traffic accidents is related to accessibility of health facilities. This analysis can be developed for all regions in Indonesia, so that it can be used as a reference for traffic stakeholders in assessing the performance of the traffic safety programs implemented. Analisis biaya kecelakaan lalu lintas diperlukan untuk memprediksi potensi kerugian negara akibat timbulnya korban kecelakaan lalu lintas. Biaya kecelakaan lalu lintas di Indonesia dibangun berdasarkan karakteristik kota Bandung tahun 2003, dan diperlihatkan bahwa biaya kecelakaan lalu lintas dapat bervariasi sesuai dengan karakteristik wilayah. Penelitian ini mencoba membandingkan pendekatan analisis di Bandung tahun 2003 dengan pendekatan Indeks Harga Konsumen dan Indeks Pembangunan Manusia untuk suatu wilayah dengan aksesibilitas menengah, yakni Lombok Timur, Provinsi Nusa Tenggara Barat. Lokasi kecelakaan lalu lintas sangat mempengaruhi biaya kecelakaan lalu lintas, karena biaya di jalan antar kota relatif lebih tinggi dibandingkan dengan biaya di jalan dalam kota. Penelitian ini meperlihatkan bahwa biaya kecelakaan lalu lintas terkait dengan aksesibilitas fasilitas kesehatan. Analisis ini dapat dikembangkan untuk semua wilayah di Indonesia, sehingga dapat dijadikan acuan bagi pemangku kepentingan lalu lintas dalam menilai kinerja program keselamatan lalu lintas yang dijalankan.

scholarly journals Modeling and Application of Pedestrian Safety Conflict Index at Signalized Intersections

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Wei Cheng ◽  
Ning Zhang ◽  
Wei Li ◽  
Jianfeng Xi
Keyword(s):  
Safety Evaluation ◽  
Pedestrian Safety ◽  
Evaluation Study ◽  
Signalized Intersections ◽  
Safety Level ◽  
Intersection Safety ◽  
Road Users ◽  
Traffic Conflict ◽  
Vulnerable Road Users ◽  
The City

Traffic conflict between turning vehicles and pedestrians is the leading cause of pedestrian fatalities at signalized intersections. In order to provide a solution for evaluating intersection safety for vulnerable road users, this paper first determines the most important factors in analyzing pedestrian-vehicle conflict and puts forward a pedestrian safety conflict index (SCI) model to establish a quantitative standard for safety evaluation of two- or multiphase intersections. A safety level system is then designed based on SCI to help categorize and describe the safety condition of intersections applicable to the model. Finally, the SCI model is applied to the evaluation of two intersections in the city of Changchun, the result of which complies with expectation, indicating the model’s potential in providing an improved approach for pedestrian-vehicle conflict evaluation study.

scholarly journals KORBAN KECELAKAAN LALU LINTAS SEPEDA MOTOR DI KOTA BANDUNG

Jurnal HPJI ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 129-136
Author(s):  
An An Anisarida ◽  
Wimpy Santosa
Keyword(s):  
Traffic Safety ◽  
Traffic Accident ◽  
Traffic Accidents ◽  
Depth Study ◽  
The City ◽  
High Chance

Abstract The number of traffic accidents, including motorcycle traffic accidents in the City of Bandung in 2013–2017 tends to decrease. However, traffic accidents involving motorbikes still dominate traffic accidents that occur. The proportion of traffic accidents involving motorbikes is still the highest compared to those of other traffic accidents, and reaches a maximum in 2015, which is 93% of the number of traffic accidents in the City of Bandung. In addition, the chance of death in motorcycle traffic accidents is still relatively high, which is between 9% and 21%. The high chance of death victims requires a more in-depth study to improve traffic safety, especially in motorcycle use. Keywords: traffic accidents, motorcycle traffic accidents, traffic accident victims, traffic safety  Abstrak Jumlah kecelakaan lalu lintas, termasuk kecelakaan lalu lintas sepeda motor di Kota Bandung pada tahun 2013–2017 cenderung mengalami penurunan. Walaupun demikian, kecelakaan lalu lintas yang melibatkan sepeda motor masih mendominasi kecelakaan lalu lintas yang terjadi. Proporsi kecelakaan lalu lintas yang melibatkan sepeda motor masih yang terbesar dibandingkan dengan kejadian kecelakaan lalu lintas yang lain, dan mencapai maksimum pada tahun 2015, yaitu 93% terhadap jumlah kecelakaan lalu lintas di Kota Bandung. Selain itu, peluang terjadinya korban meninggal dunia dalam kecelakaan lalu lintas sepeda motor masih relatif tinggi, yaitu antara 9% hingga 21%. Tingginya peluang terjadinya korban meninggal dunia ini membutuhkan penelitian yang lebih mendalam untuk meningkatkan keselamatan berlalu lintas, khususnya dalam penggunaan sepeda motor. Kata-kata kunci: kecelakaan lalu lintas, kecelakaan lalu lintas sepeda motor, korban kecelakaan lalu lintas, keselamatan lalu lintas

scholarly journals A database development and analysis of selected side impact collisions in Toronto

2021 ◽  
Author(s):  
John Zaki Bou-Younes
Keyword(s):  
Traffic Accidents ◽  
Side Impact ◽  
Vehicle Speed ◽  
Software Release ◽  
Late Model ◽  
The City ◽  
Different Sources ◽  
Insight Into ◽  
Statistical Analysis Software ◽  
Selection Of

This thesis is based on the initial phase of a project that developed an in-depth collision database and performed an analysis of police reported side-impact collisions for the City of Toronto intersections between 1998 and 2000. Currently, collision data exists through several different sources in Ontario. The development of a database involving the amalgamation of collision forms, the selection of data fields, and the collection of real collision data from selected, thoroughly investigated side impact collisions involving late model vehicles (1998 and newer), is described. For analysis, Statistical Analysis Software Release 8.02 was used to investigate causation and causal factors of side impact collisions. Statistically significant collision factors determined by fault propensity included apparent driver action, driver age, front seat passenger age, maximum posted speed, approximate vehicle speed, road character, and number of lanes. For intersection collision propensity, statistically significant findings included the system used, presence of flashing signals, intersection legs, roadway volume, and intersection leg road classifications. It is anticipated that the findings from this analysis can provide insight into significant factors in side-impact collisions that will be applied with greater focus to the in-depth collision database, once developed. Traffic accidents

scholarly journals A database development and analysis of selected side impact collisions in Toronto

2021 ◽  
Author(s):  
John Zaki Bou-Younes
Keyword(s):  
Traffic Accidents ◽  
Side Impact ◽  
Vehicle Speed ◽  
Software Release ◽  
Late Model ◽  
The City ◽  
Different Sources ◽  
Insight Into ◽  
Statistical Analysis Software ◽  
Selection Of

This thesis is based on the initial phase of a project that developed an in-depth collision database and performed an analysis of police reported side-impact collisions for the City of Toronto intersections between 1998 and 2000. Currently, collision data exists through several different sources in Ontario. The development of a database involving the amalgamation of collision forms, the selection of data fields, and the collection of real collision data from selected, thoroughly investigated side impact collisions involving late model vehicles (1998 and newer), is described. For analysis, Statistical Analysis Software Release 8.02 was used to investigate causation and causal factors of side impact collisions. Statistically significant collision factors determined by fault propensity included apparent driver action, driver age, front seat passenger age, maximum posted speed, approximate vehicle speed, road character, and number of lanes. For intersection collision propensity, statistically significant findings included the system used, presence of flashing signals, intersection legs, roadway volume, and intersection leg road classifications. It is anticipated that the findings from this analysis can provide insight into significant factors in side-impact collisions that will be applied with greater focus to the in-depth collision database, once developed. Traffic accidents

Safety Evaluation of Freight Intermodal Connectors in Tennessee State

2019 ◽  
Vol 2673 (3) ◽  
pp. 237-246
Author(s):  
Deo Chimba ◽  
Emmanuel Masindoki ◽  
Xiaoming Li ◽  
Casey Langford
Keyword(s):  
Traffic Safety ◽  
Statistical Significance ◽  
Safety Evaluation ◽  
Crash Frequency ◽  
Left Turn ◽  
Crash Rates ◽  
Signal Density ◽  
Geometric Factors ◽  
Last Mile ◽  
Average Annual Daily Traffic

This paper evaluates the traffic safety along freight intermodal connectors (FICs), which are also known as “first mile/last mile roadways,” connecting facilities that link freight-intensive land uses to main freight routes. Using Tennessee’s FICs as a case study, the paper digests the safety with reference to crash frequency, crash rates, and statistical significance of attributing traffic and geometric factors. It was found that connectors leading to pipeline terminals have high crash rates (almost double) compared with other type of terminals, whereas port terminal connectors have the lowest safety problem indices. The study established correlative contributing causes of crash frequencies and rates along FICs that included average annual daily traffic, lanes, shoulders, access, and median types. Traffic signal density was found to strongly and significantly affect the probability of crashes, together with the presence of a two-way left-turn lane (TWLTL), which surprisingly tends to decrease the probability of crashes along these connectors. The presence of shoulders along intermodal connectors was found to help reduce the probability of crashes, whereas the presence of curb and gutter tends to increase crash frequency. Analysis indicated that most of the FICs with high crash rates were also operating at a lower traffic operations level of service (LOS), especially for critical movements toward freight facilities because of high truck volumes.

Safety Performance Functions for Signalized Intersections in Large Urban Areas

2005 ◽  
Vol 1908 (1) ◽  
pp. 165-171 ◽  
Author(s):  
Craig Lyon ◽  
Anwar Haq ◽  
Bhagwant Persaud ◽  
Steven T. Kodama
Keyword(s):  
Urban Areas ◽  
Empirical Bayes ◽  
Signalized Intersections ◽  
Safety Performance ◽  
Signalized Intersection ◽  
Left Turn ◽  
Side Impacts ◽  
Recent Interest ◽  
Safety Performance Functions ◽  
Network Screening

This paper describes the development of safety performance functions (SPFs) for 1,950 urban signalized intersections on the basis of 5 years of collision data in Toronto, Ontario, Canada. Because Toronto has one of the largest known, readily accessible, urban signalized intersection databases, it was possible to develop reliable, widely applicable SPFs for different intersection classifications, collision severities, and impact types. Such a comprehensive set of SPFs is not available for urban signalized intersections from data for a single jurisdiction, despite the considerable recent interest in use of these functions for analyses related to network screening, and the development, prioritization, and evaluation of treatments. The application of a straightforward recalibration process requiring relatively little data means that the SPFs calibrated can be used by researchers and practitioners for other jurisdictions for which these functions do not exist and are unlikely to exist for some time. The value of the functions is illustrated in an application to evaluate a topical safety measure—left-turn priority treatment for which existing knowledge is on a shaky foundation. The results of this empirical Bayes evaluation show that this treatment is quite effective for reducing collisions, particularly those involving left-turn side impacts.

Research on the Model of Road Traffic Safety Evaluation Based on Synergetics Theory

2013 ◽  
Vol 779-780 ◽  
pp. 1028-1035 ◽  
Author(s):  
Fei Chen ◽  
Song Ling Chen ◽  
Ying Ying Cheng
Keyword(s):  
Traffic Safety ◽  
Traffic Accidents ◽  
Field Survey ◽  
Road Traffic ◽  
Safety Evaluation ◽  
Road Traffic Safety

In order to evaluate the level of roads safety, this paper proposes a model of traffic accidents which is derived from theories of synergetics. In this study, a great deal of field survey date is obtained via a set of physiological and psychological detection devices. By analyzing data combined with driving comfort threshold, a model of traffic accidents is founded according to different effects, caused by traffic factors.

scholarly journals Safety evaluation of unconventional outside left-turn lane using automated traffic conflict techniques

2016 ◽  
Vol 43 (7) ◽  
pp. 631-642 ◽  
Author(s):  
Yanyong Guo ◽  
Tarek Sayed ◽  
Mohamed H. Zaki ◽  
Pan Liu
Keyword(s):  
Urban Areas ◽  
Safety Evaluation ◽  
Signalized Intersections ◽  
Video Data ◽  
Contributing Factors ◽  
Left Turn ◽  
Time To Collision ◽  
Traffic Conflicts ◽  
Traffic Conflict ◽  
The Right

The objective of this study is to evaluate the safety impacts of unconventional outside left-turn lane at signalized intersections. New designed unconventional outside left-turn lanes are increasingly used at signalized intersections in urban areas in China. The unconventional outside left-turn lane design allows an exclusive left-turn lane to be located to the right of through lanes to improve the efficiency and increase the capacity of left-turn movements. However, the design also raises some concerns regarding potential negative safety impacts. The evaluation is conducted using an automated video-based traffic conflict technique. The traffic conflicts approach provides better understanding of collision contributing factors and the failure mechanism that leads to road collisions. Traffic conflicts are automatically detected and time to collision is calculated based on the analysis of the vehicles’ positions in space and time. Video data are collected from a signalized intersection in Nanjing, China, where both traditional inside and unconventional outside left-turn lanes are installed on two intersection approaches. The other two approaches have only inside left-turn lanes. The study compared frequency and severity of conflict for left-turning vehicles as well as the percentage of vehicles involved in conflicts from the inside and outside left-turn lanes. The results show that the intersection approaches with outside left-turn lanes had considerably more conflicts compared to approaches without outside left-turn lanes. As well, the approaches with outside left-turn lanes had significantly higher conflict severity than the approaches without outside left-turn lanes. As such, it is recommended that the trade-off between the improved mobility and negative safety impact of outside left-turn lanes be carefully considered before recommending their installation.

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