scholarly journals A Novel Surrogate Safety Indicator Based on Constant Initial Acceleration and Reaction Time Assumption

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Adrian Fazekas ◽  
Friederike Hennecke ◽  
Eszter Kalló ◽  
Markus Oeser

The development of surrogate safety measures has drawn significant research interest in the field of traffic safety analysis. Innovative data sources such as video-based traffic surveillance systems have made it possible to collect large amounts of microscopic traffic data. By deriving traffic safety indicators such as the Deceleration Rate to Avoid a Crash (DRAC) statements concerning traffic safety over a determined road section can be made. This work presents the derivation of a novel surrogate safety indicator based on a Constant Initial Acceleration and reaction time assumption which considers the interaction between vehicles and describes the traffic safety of a road section. The evaluation is based on a video-based microscopic traffic data collection. To examine the efficiency, the new developed indicator is compared to the original Deceleration Rate to Avoid a Crash (DRAC) and the modified indicator (MDRAC) which includes the reaction time. The results showed that the new indicator is more sensitive in detecting critical situations than the other indicators and in addition describes the conflict situations more realistically.

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Choong Heon Yang ◽  
Jin Guk Kim ◽  
Sung Pil Shin

Road surface conditions have a direct effect on the quality of driving, which in turn affects overall traffic flow. Many studies have been conducted to accurately identify road surface conditions using diverse technologies. However, these previously proposed methods may still be insufficient to estimate actual risks along the roads because the exact road risk levels cannot be determined from only road surface damage data. The actual risk level of the road must be derived by considering both the road surface damage data as well as other factors such as speed. In this study, the road hazard index is proposed using smartphone-obtained pothole and traffic data to represent the level of risk due to road surface conditions. The relevant algorithm and its operating system are developed to produce the estimated index values that are classified into four levels of road risk. This road hazard index can assist road agencies in establishing road maintenance plans and budgets and will allow drivers to minimize the risk of accidents by adjusting their driving speeds in advance of dangerous road conditions. To demonstrate the proposed risk hazard assessment methodology, road hazards were assessed along specific test road sections based on observed pothole and historical travel speed data. It was found that the proposed methodology provides a rational method for improving traffic safety.


Author(s):  
Zhenyao Zhang ◽  
Jianying Zheng ◽  
Hao Xu ◽  
Xiang Wang

The problem of traffic safety has become increasingly prominent owing to the increase in the number of cars. Traffic accidents often occur in an instant, which makes it necessary to obtain traffic data with high resolution. High-resolution micro traffic data (HRMTD) indicates that the spatial resolution reaches the centimeter level and that the temporal resolution reaches the millisecond level. The position, direction, speed, and acceleration of objects on the road can be extracted with HRMTD. In this paper, a LiDAR sensor was installed at the roadside for data collection. An adjacent-frame fusion method for vehicle detection and tracking in complex traffic circumstances is presented. Compared with the previous research, objects can be detected and tracked without object model extraction or a bounding box description. In addition, problems caused by occlusion can be improved using adjacent frames fusion in the vehicle detection and tracking algorithms in this paper. The data processing procedure are as follows: selection of area of interest, ground point removal, vehicle clustering, and vehicle tracking. The algorithm has been tested at different sites (in Reno and Suzhou), and the results demonstrate that the algorithm can perform well in both simple and complex application scenarios.


2007 ◽  
Vol 60 (7-8) ◽  
pp. 365-371
Author(s):  
Predrag Djuric ◽  
Danka Filipovic

Different aspects of driver personality may affect traffic safety. Extended driver reaction time causes deceleration of the reflexes, which is a major cause of traffic accidents. Cornell index was used in 30 drivers responsible for traffic accidents, with the aim to measure their level of neurotic disorder and compare them with results of controls (drivers not responsible for traffic accidents). Reaction time was measured and compared among subjects with normal results of Cornell test and those with pathological findings. Drivers causing traffic accidents showed significantly higher Cornell index scores than drivers not responsible for traffic accidents. Drivers with pathological results of Cornell index showed a significantly longer reaction time.


2012 ◽  
Vol 1 (1) ◽  
pp. 1-9
Author(s):  
Alina Burlacu ◽  
Mihai Dicu ◽  
Valentin Anton

Abstract In Romania, with time, settlements located along the main roads have developed and transformed into linear towns, with significant local and connection traffic, important administrative, economic, commercial and touristic activities concentrated in the central area, as well as pedestrian traffic of over 200 pedestrians per hour in the main pedestrian crossings on the route. The object of the present study is made by a series of junctions situated on National Road 1 in Busteni town, on a dangerous road sector. For this study, traffic measurements, simulations and suggestions for improving the existing situation were made. Based on the simulated traffic flows, there were performed capacity analysis with PTV Vissim and Traficware Synchro softwares, and were developed appropriate planning solutions for the intersections, resulting in tables with extracted performance indicators based on micro simulation of the traffic values. Also planning solutions for horizontal design and proposals for traffic lights were made for junctions that can not operate under priority traffic on one direction or which are presenting traffic safety risk. Based on the traffic data, it was taken in consideration the necessity to make planning proposals and to develop design solutions immediately applicable, with minimum intervention. Solutions will refer to the geometric planning of the intersections, but with new plans and timings for traffic lights, including proposals for new equipment; regulating the traffic flow: development/ refurbishment of intersections and pedestrian crossings; optimization of routing programs in order to achieve a higher level of service and more efficient traffic control indicators; segregation of pedestrian movements by vehicles traffic, implementation of physical devices to lock / channel the traffic.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Li-Li Dong ◽  
Peng Liu ◽  
Qi Lou ◽  
Wen-Hai Xu

Judicious use of lamps is of profound significance to improve the internal traffic safety of tunnels. This study evaluated the biological effects of spectrum on human visual and nonvisual under mesopic vision category. According to the difference of human eyes’ response to the visual and nonvisual biological effects of different wavelengths of light radiation, a method of applying the mesopic visual spectral luminous efficiency curve to the assessment of nonvisual biological effects and blue light hazards is proposed. The results show that, in theory, under mesopic vision category, the spectrum with high correlation color temperature (CCT) and high color rendering index (CRI) has higher blue light content Z-value and has greater impact on human nonvisual effects and blue light radiation damage, but it can also provide higher human perception luminance. The visual effect detection experiment of driving in the interior zones of the tunnel is simulated in the laboratory, and the critical flicker frequency and reaction time are taken as physiological indexes. The results show that the spectrum with high CCT and high CRI corresponds to lower critical flicker frequency drop value and faster reaction time, which has a positive effect on improving driving safety. Therefore, this paper suggests that the LED with high CCT and high CRI (CCT = 6500 K, CRI2012 = 95) should be used in the interior zones of the tunnel with relatively short lighting section, and the CCT and CRI should be appropriately reduced in other road environments with long lighting section to reduce the impact of spectrum on nonvisual photobiology, so as to improve road traffic safety.


Author(s):  
Ali Payıdar AKGÜNGÖR ◽  
Elif Zahide MERCAN

Intersections, for vehicles coming from different directions, are conflict points in road networks. When a driver approaching a signalised intersection encounters the yellow light, he/she is in a dilemma either to safely stop or to pass through the intersection during clearance time. The decision to stop or to pass may change depending on some factors such as duration of yellow light, deceleration and acceleration rate, width of intersection, speed and length of vehicle, etc. This study aims to put forth the effects of some related factors affecting the length of the Type I dilemma zone. To perform this study, five factors including vehicle speed, maximum deceleration rate, perception-reaction time, clearance time, the total intersection width-vehicle length were considered and a total of 648 different traffic cases were investigated. The study results showed that the Type I dilemma zone length increased with the increase of speed, total intersection width-vehicle length and perception-reaction time, but decreased with the increase of clearance time and deceleration rate.


Sensors ◽  
2021 ◽  
Vol 21 (24) ◽  
pp. 8215
Author(s):  
Małgorzata Dudzińska ◽  
Agnieszka Dawidowicz

The encroachment of wild boars into urban areas is a growing problem. The occurrence of wild boars in cities leads to conflict situations. Socio-spatial conflicts can escalate to a varied degree. Assessments of these conflicts can be performed by analyzing spatial data concerning the affected locations and wild boar behaviors. The collection of spatial data is a laborious and costly process that requires access to urban surveillance systems, in addition to regular analyses of intervention reports. A supporting method for assessing the risk of wild boar encroachment and socio-spatial conflict in cities was proposed in the present study. The developed approach relies on big data, namely, multimedia and descriptive data that are on social media. The proposed method was tested in the city of Olsztyn in Poland. The main aim of this study was to evaluate the applicability of data crowdsourced from a popular social networking site for determining the location and severity of conflicts. A photointerpretation method and the kernel density estimation (KDE) tool implemented in ArcGIS Desktop 10.7.1 software were applied in the study. The proposed approach fills a gap in the application of crowdsourcing data to identify types of socio-spatial conflicts involving wild boars in urban areas. Validation of the results with reports of calls to intervention services showed the high coverage of this approach and thus the usefulness of crowdsourcing data.


Sign in / Sign up

Export Citation Format

Share Document