scholarly journals A Surrogate Video-Based Safety Methodology for Diagnosis and Evaluation of Low-Cost Pedestrian-Safety Countermeasures: The Case of Cochabamba, Bolivia

2019 ◽  
Vol 11 (17) ◽  
pp. 4737
Author(s):  
Lynn Scholl ◽  
Mohamed Elagaty ◽  
Bismarck Ledezma-Navarro ◽  
Edgar Zamora ◽  
Luis Miranda-Moreno
Keyword(s):  
Developing Countries ◽  
Latin American ◽  
Traffic Safety ◽  
Road Safety ◽  
Low Cost ◽  
Video Data ◽  
Crash Risk ◽  
Video Analytics ◽  
Crash Data ◽  
Safety Countermeasures

Due to a lack of reliable data collection systems, traffic fatalities and injuries are often under-reported in developing countries. Recent developments in surrogate road safety methods and video analytics tools offer an alternative approach that can be both lower cost and more time efficient when crash data is incomplete or missing. However, very few studies investigating pedestrian road safety in developing countries using these approaches exist. This research uses an automated video analytics tool to develop and analyze surrogate traffic safety measures and to evaluate the effectiveness of temporary low-cost countermeasures at selected pedestrian crossings at risky intersections in the city of Cochabamba, Bolivia. Specialized computer vision software is used to process hundreds of hours of video data and generate data on road users’ speed and trajectories. We find that motorcycles, turning movements, and roundabouts, are among the key factors related to pedestrian crash risk, and that the implemented treatments were effective at four-legged intersections but not at traditional-design roundabouts. This study demonstrates the applicability of the surrogate methodology based on automated video analytics in the Latin American context, where traditional methods are challenging to implement. The methodology could serve as a tool to rapidly evaluate temporary treatments before they are permanently implemented and replicated.

Traffic Safety Region Estimation Based on SFS–PCA–LSSVM: An Application to Highway Crash Risk Evaluation

2016 ◽  
Vol 26 (09n10) ◽  
pp. 1555-1570
Author(s):  
Yanfang Yang ◽  
Yong Qin ◽  
Limin Jia ◽  
Honghui Dong
Keyword(s):  
State Space ◽  
Real Time ◽  
Traffic Safety ◽  
Risk Evaluation ◽  
Crash Risk ◽  
Support Vector ◽  
State Variables ◽  
Crash Data ◽  
Traffic State ◽  
Safe Condition

Accurate real-time crash risk evaluation is essential for making prevention strategy in order to proactively improve traffic safety. Quite a number of models have been developed to evaluate traffic crash risk by using real-time surveillance data. In this paper, the basic idea of traffic safety region is introduced into highway crash risk evaluation. Sequential forward selection (SFS), principal components analysis (PCA) and least squares support vector machine (LSSVM) are used to estimate the traffic safety region and classify the traffic states (safe condition and unsafe condition). The proposed method works by first extracting state variables from the observed traffic variables. Two statistics [Formula: see text] and squared prediction error (SPE) are calculated by SFS–PCA and used as the final state variables for traffic state space. Next, LSSVM is used to estimate the boundary of traffic safety region and identify the traffic states in the traffic state space. To demonstrate the advantage of the proposed method, this study develops two crash risk evaluation models, namely SFS–LSSVM model and PCA–LSSVM model, based on crash data and non-crash data collected on freeway I-880N in Alameda. Validation results show that the method is of reasonably high accuracy for identifying traffic states.

scholarly journals Assessment of traffic safety at median openings using surrogate safety measures: a case study in India

2020 ◽  
Vol 80 (ET.2020) ◽  
pp. 1-12
Author(s):  
Malaya Mohanty
Keyword(s):  
Developing Countries ◽  
Traffic Safety ◽  
Transportation Engineering ◽  
Crash Data ◽  
Road Crashes ◽  
The Road ◽  
Sight Distance ◽  
Traffic Volumes ◽  
Road Crash ◽  
Stopping Sight Distance

Traffic safety is an integral part of transportation engineering. In developing countries, its importance is even more. Additionally, at uncontrolled median openings, the severity of road crashes increase many fold. Conventionally, road crash data were used to analyse safety. However, in developing countries, the accuracy of this data is highly questionable. Therefore, in this study, a new technique in addition to post encroachment time (PET), which is a surrogate safety measure is used to predict the severity of probable road crashes at median openings. After the extraction of PET values from field data, they have been compared with the minimum braking times obtained from calculation of minimum stopping sight distance. The comparison shows that while the number of road crashes may be less at lower traffic volume levels, however the severity of those crashes is much higher as compared to the road crashes occurring at high traffic volumes.

scholarly journals Application Of Safety Inspections For Evaluation Of Two – Lane Regional Roads In Poland

2014 ◽  
Vol 60 (4) ◽  
pp. 453-474 ◽  
Author(s):  
S. Cafiso ◽  
M. Kieć ◽  
M. Milazzo ◽  
G. Pappalardo ◽  
F. Trovato
Keyword(s):  
Traffic Safety ◽  
Road Safety ◽  
Road Network ◽  
Low Cost ◽  
Evaluation Criteria ◽  
Rural Roads ◽  
Safety Hazard ◽  
Safety Issues ◽  
Good Agreement ◽  
Safety Inspections

AbstractIn the paper methods for conducting Road Safety Inspections (SIs) in Italy and Poland are described and compared. The goal of the study is to improve the quality and efficiency of the safety inspections of road network by using low cost equipment (GPS, Tablet, Camera) and specific software. Particular attention was paid to the need for proper calibration of factors, causing traffic safety hazard associated with road infrastructure. The model developed according to the Italian procedures was adapted to comply with the checklists and evaluation criteria of the Polish guidelines. Overall, a good agreement between the two approaches was identified, however some modification was required to include new safety issues, characteristic for the Polish network for safety inspection of two lane rural roads. To test the applicability about 100 km of regional two lane roads in Poland were inspected with Polish and Italian procedures.

scholarly journals Predicting Wet-Road Crashes Using the Finite-Mixture Zero-Truncated Negative Binomial Model

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ying Chen ◽  
Zhongxiang Huang
Keyword(s):  
Traffic Safety ◽  
Negative Binomial ◽  
Safety Data ◽  
Method Comparison ◽  
Weather Conditions ◽  
Finite Mixture ◽  
Crash Risk ◽  
Crash Data ◽  
Road Crashes ◽  
Inclement Weather

Inclement weather affects traffic safety in various ways. Crashes on rainy days not only cause fatalities and injuries but also significantly increase travel time. Accurately predicting crash risk under inclement weather conditions is helpful and informative to both roadway agencies and roadway users. Safety researchers have proposed various analytic methods to predict crashes. However, most of them require complete roadway inventory, traffic, and crash data. Data incompleteness is a challenge in many developing countries. It is common that safety researchers only have access to data on sites where a crash has occurred (i.e., zero-truncated data). The conventional crash models are not applicable to zero-truncated safety data. This paper proposes a finite-mixture zero-truncated negative binomial (FMZTNB) model structure. The model is applied to three-year wet-road crash data on 395 divided roadway segments (total 586 km), and the parameters are estimated using the Markov chain Monte Carlo (MCMC) method. Comparison indicates that the proposed FMZTNB model has better fitting performance and is more accurate in predicting the number of wet-road crashes. The model is capable of capturing the heterogeneity within the sample crash data. In addition, lane width showed mixed effects in different components on wet-road crashes, which are not observed in conventional modeling approaches. Practitioners are encouraged to consider the finite-mixture zero-truncated modeling approach when complete safety dataset is not available.

scholarly journals Microsimulation and the Evaluation of Safety Levels in the Presence of Roadside Obstacles

2020 ◽  
pp. 1-12
Author(s):  
Vittorio Astarita
Keyword(s):  
Traffic Safety ◽  
Road Safety ◽  
Road Network ◽  
Crash Risk ◽  
Traffic Flows ◽  
Ongoing Research ◽  
The Road ◽  
Fatal Crashes ◽  
First Results ◽  
Single Vehicle

Traffic microsimulation has been used for the analysis of road safety. In particular, some studies have confirmed that the reproduction by simulation of user behaviour under different traffic flows and geometry conditions can identify near crashes events that are a good base to estimate real crash risk. According to recent researches it appears that microsimulation tools can evaluate road safety performance and allow engineers to take appropriate countermeasures at specific points of the road network. The results of these approaches have been promising, though, all ongoing research has overlooked one important issue in the estimation of traffic safety levels: single vehicle crashes. According to statistics, collisions with fixed objects result in above 40% of all vehicle fatal crashes. Common used safety indicators are limited in their application since, in fact, they are based on conflicts techniques that do not consider roadside obstacles and barriers. The objective of this paper is to present a specific application of microsimulation software which is able to consider also potential conflicts with roadside objects. A specific microsimulation model add-on has been developed for the estimation of new road safety indicators that considers also potential crashes with roadside objects. First results are very promising and the developed software was applied on Tritone microsimulation package and can be used as an add-on also for other common used microsimulation packages such as Vissim and Aimsun.

scholarly journals Real-Time Crash-Risk Optimization at Signalized Intersections

2021 ◽  
pp. 036119812110628
Author(s):  
Passant Reyad ◽  
Tarek Sayed ◽  
Mohamed Essa ◽  
Lai Zheng
Keyword(s):  
Real Time ◽  
Traffic Safety ◽  
Traffic Congestion ◽  
Prediction Models ◽  
Value Theory ◽  
Signalized Intersections ◽  
Video Data ◽  
Crash Risk ◽  
Traffic Signal Control ◽  
Real Time Traffic

Over the past few decades, numerous adaptive traffic signal control (ATSC) algorithms have been proposed to alleviate traffic congestion and optimize traffic mobility using real-time traffic data, such as data from connected vehicles (CVs). However, most of the existing ATSC algorithms do not consider optimizing traffic safety, likely because of the lack of tools to evaluate safety in real time. In this paper, we propose a novel ATSC algorithm for real-time safety optimization. The algorithm utilizes a traditional Reinforcement Learning approach (i.e., Q-learning) as well as recently developed extreme value theory (EVT) real-time crash prediction models. The algorithm was validated using real-world traffic video data collected from two signalized intersections in British Columbia. The results indicated that, compared with an existing fully actuated signal controller, the developed algorithm can significantly reduce the real-time crash risk by 43% to 45% at the intersection’s approaches even at low CVs market penetration rates.

Modernization of the water utility company of Bogotá (Colombia): an example of public and private participation for solving management problems of water companies in developing countries

2005 ◽  
Vol 5 (2) ◽  
pp. 107-113
Author(s):  
F. Zuleta ◽  
A. Merlano ◽  
A. Alvarez ◽  
M. Montoya ◽  
E. Restrepo
Keyword(s):  
Developing Countries ◽  
Latin American ◽  
Public Management ◽  
Practical Case ◽  
Water Utility ◽  
Comparative Efficiency ◽  
Utility Company ◽  
Private Participation ◽  
Management Problems ◽  
Water Companies

A common characteristic of water utility and wastewater companies in developing countries is management problems and limited commercial vocation. In the biggest Latin American cities there is a level of infrastructure enough for providing a substantially better service than the one currently supplied to their badly served customers. For years decisions have moved between two extremes: public management – usually corrupted with playing politics and inefficiency problems, and privatization – sharply criticized by many, and which has shown tendencies to inequality that leave it far away from earning panacea status. This paper is intended to expose the advantages of a novel model in which a state-run company with commercial management problems, the EAAB, solves its limitations by keeping the ownership of its assets and successfully incorporating the participation of better practices from other specialized operators, one of which is a state-owned player, EEPPM. This scheme demonstrates how the service indicators of a system serving eight million inhabitants in the Colombian capital improved significantly with state-owned assets and private participation, without giving in to privatization pressures or stagnating in the usual inefficiency typical of public management in developing countries. This is proposed as a replicable experience that can be used in medium and large cities in other countries with similar management problems, with certain adjustments to fit the solution to the specific cases. This is also a practical case for conducting a comparison of competitiveness within a city, of interest for regulatory entities and investigators on the potential of comparative efficiency in a traditionally monopolistic industry.

Low-Cost Technology for Water Pollution Control in Developing Countries

1982 ◽  
Vol 14 (9-11) ◽  
pp. 1337-1352 ◽  
Author(s):  
G G Cillié
Keyword(s):  
Water Pollution ◽  
Developing Countries ◽  
United Nations ◽  
Pollution Control ◽  
Low Cost ◽  
Water Pollution Control ◽  
Local Labour ◽  
International Water ◽  
Design And Methods ◽  
Local Materials

An estimated 80 % of all illnesses in developing countries is in one way or another related to water. In order to alleviate this most serious condition, the united Nations has initiated the “International Water Decade”, for which the estimated costs are $600 000 million, a sum which is far beyond any available means. By application of “low-cost technology” this sum could be reduced to $100 000 million which brings the objective within the reach of possibility. Details are given of the design and methods of construction of units which are best suited to the specific requirements and which would be simple, reliable and economical to operate. These can be constructed largely from local materials and by local labour. The need for appropriate training of both operators and the user population is stressed.

scholarly journals Evaluating the Safety Risk of Rural Roadsides Using a Bayesian Network Method

2019 ◽  
Vol 16 (7) ◽  
pp. 1166 ◽  
Author(s):  
Tianpei Tang ◽  
Senlai Zhu ◽  
Yuntao Guo ◽  
Xizhao Zhou ◽  
Yang Cao
Keyword(s):  
Bayesian Network ◽  
Low Cost ◽  
Road Networks ◽  
Access Point ◽  
Safety Risk ◽  
Crash Data ◽  
Risk Levels ◽  
The Road ◽  
Run Off ◽  
Point Density

Evaluating the safety risk of rural roadsides is critical for achieving reasonable allocation of a limited budget and avoiding excessive installation of safety facilities. To assess the safety risk of rural roadsides when the crash data are unavailable or missing, this study proposed a Bayesian Network (BN) method that uses the experts’ judgments on the conditional probability of different safety risk factors to evaluate the safety risk of rural roadsides. Eight factors were considered, including seven factors identified in the literature and a new factor named access point density. To validate the effectiveness of the proposed method, a case study was conducted using 19.42 km long road networks in the rural area of Nantong, China. By comparing the results of the proposed method and run-off-road (ROR) crash data from 2015–2016 in the study area, the road segments with higher safety risk levels identified by the proposed method were found to be statistically significantly correlated with higher crash severity based on the crash data. In addition, by comparing the respective results evaluated by eight factors and seven factors (a new factor removed), we also found that access point density significantly contributed to the safety risk of rural roadsides. These results show that the proposed method can be considered as a low-cost solution to evaluating the safety risk of rural roadsides with relatively high accuracy, especially for areas with large rural road networks and incomplete ROR crash data due to budget limitation, human errors, negligence, or inconsistent crash recordings.

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