Impact of Congestion and Traffic Flow on Crash Frequency and Severity: Application of Smartphone-Collected GPS Travel Data

2017 ◽  
Vol 2659 (1) ◽  
pp. 43-54 ◽  
Author(s):  
Joshua Stipancic ◽  
Luis Miranda-Moreno ◽  
Nicolas Saunier
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Quebec City ◽  
Crash Severity ◽  
Crash Frequency ◽  
Crash Data ◽  
Instrumented Vehicles ◽  
Minor Injuries ◽  
The Impact ◽  
The Relationship

Mobility and safety are the two greatest priorities within any transportation system. Ideally, traffic flow enhancement and crash reductions could occur simultaneously, although their relationship is likely complex. The impact of traffic congestion and flow on road safety requires more empirical evidence to determine the direction and magnitude of the relationship. The study of this relationship is an ideal application for instrumented vehicles and surrogate safety measures (SSMs). The purpose of this paper is to correlate quantitative measures of congestion and flow derived from smartphone-collected GPS data with collision frequency and severity at the network scale. GPS travel data were collected in Quebec City, Quebec, Canada, and the sample for this study contained data for more than 4,000 drivers and 20,000 trips. The extracted SSMs, the congestion index (CI), average speed ( V), and the coefficient of variation of speed (CVS) were compared with crash data collected over an 11-year period from 2000 to 2010 with the use of Spearman’s correlation coefficient and pairwise Kolmogorov–Smirnov tests. The correlations with crash frequency were weak to moderate. CI was shown to be positively correlated with crash frequency, and the relationship to crash severity was found to be nonmonotonous. Higher congestion levels were related to crashes with major injuries, whereas low congestion levels were related to crashes with minor injuries and fatalities. Surprisingly, V was found to be negatively correlated with crash frequency and had no conclusive statistical relationship to crash severity. CVS was positively correlated with crash frequency and statistically related to increased crash severity. Future work will focus on the development of a network screening model that incorporates these SSMs.

scholarly journals Comparison of Factors Affecting Crash Severities in Hit-and-Run and Non-Hit-and-Run Crashes

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Bei Zhou ◽  
Zongzhi Li ◽  
Shengrui Zhang
Keyword(s):  
Comparison Group ◽  
Reference Group ◽  
Multinomial Logistic Regression ◽  
Crash Severity ◽  
Property Damage ◽  
Average Percentage ◽  
Crash Data ◽  
Hit And Run ◽  
The Impact ◽  
Average Percentage Deviation

A hit-and-run (HR) crash occurs when the driver of the offending vehicle flees the crash scene without reporting it or aiding the victims. The current study aimed at contributing to existing literatures by comparing factors which might affect the crash severity in HR and non-hit-and-run (NHR) crashes. The data was extracted from the police-reported crash data from September 2017 to August 2018 within the City of Chicago. Two multinomial logistic regression models were established for the HR and NHR crash data, respectively. The odds ratio (OR) of each variable was used to quantify the impact of this variable on the crash severity. In both models, the property damage only (PDO) crash was selected as the reference group, and the injury and fatal crash were chosen as the comparison group. When the injury crash was taken as the comparison group, it was found that 12 variables contributed to the crash severities in both HR and NHR model. The average percentage deviation of OR for these 12 variables was 34%, indicating that compared with property damage, HR crashes were 34% more likely to result in injuries than NHR crashes on average. When fatal crashes were chosen as the comparison group, 2 variables were found to be statistically significant in both the HR and the NHR model. The average percentage deviation of OR for these 2 variables was 127%, indicating that compared with property damage, HR crashes were 127% more likely to result in fatalities than NHR crashes on average.

Effects of Rural Highway Median Treatments and Access

2005 ◽  
Vol 1931 (1) ◽  
pp. 99-107 ◽  
Author(s):  
J. L. Gattis ◽  
Ramasubramaniyan Balakumar ◽  
Lynette K. Duncan
Keyword(s):  
Land Use ◽  
Crash Severity ◽  
Crash Frequency ◽  
Crash Data ◽  
Crash Rates ◽  
Access Frequency ◽  
Stop Sign ◽  
Median Volume ◽  
Rural Highway ◽  
Median Width

The safety records of rural and suburban four-lane highways in Arkansas as a function of median treatment and access density were examined. The study excluded roadways with posted speeds lower than 64 km/h (40 mph) and excluded fully controlled access roadways. When entering an urban area, the segments were normally terminated when the first traffic signal or stop sign was encountered. By using 3 years of crash data, the analyses revealed a number of relationships relating crash frequency to median, volume, and access frequency attributes. Crash severity and crash type were also examined. As median width increased, there was a weak but statistically significant decline in the crash rate. There was a weak but statistically significant increase in the crash rate as access density increased. The roadways with shoulders and depressed medians had the lowest crash rates, and the roadways with no median (i.e., painted centerline) and curbs had the worst safety record. An inspection of these data suggests that there may be a correlation between median type and land use type: certain types of median are more likely to be present in certain land use environments. This raises the possibility that in this and in other studies of the safety effects of median treatments, the findings may be influenced or skewed by correlations between median type and land use or surroundings or by other factors.

scholarly journals Exploring the Connections between Land Use and Transportation: A Case Study of Shaheb Bazar to Rail Gate Road, Rajshahi City

2019 ◽  
Vol 10 (1) ◽  
pp. 30-40 ◽  
Author(s):  
Dulal Sarker ◽  
Abdur Rouf Khan ◽  
Muhaiminul Islam
Keyword(s):  
Land Use ◽  
Traffic Congestion ◽  
Management Strategies ◽  
Travel Behaviour ◽  
Reciprocal Relationship ◽  
Land Use Pattern ◽  
Common Technique ◽  
The Impact ◽  
The Relationship ◽  
Rajshahi City

Abstract Land use-transportation comprehensive planning has become an increasingly common technique in regional and sub-regional planning processes. Since land use management strategies act as an effective tool to achieve transportation planning objectives, it is important to identify the relationship between land use pattern and travel behaviour. This study examined the relationship between transportation and land use in Rajshahi city. Rajshahi is a major urban, commercial and educational centre of Bangladesh. In Rajshahi, Shaheb bazaar zero points to New Market road is one of the most important roads. After construction of this road in 2013 intense development has taken place beside it. To identify this primary relationship data has been collected from different types of field survey. Then the impact of land use and transportation has been determined by comparing with the previous database. The findings of the study show that there exist a reciprocal relationship between land use and transportation system and the impacts on both. The study also notes that the impact of transportation on land use is more than the impact of land use on transportation. The study will help to control the haphazard growth and traffic congestion of the concerned area in the future.

EFFECT OF RAINFALL ON TRAFFIC FLOW CHARACTERISTICS DURING NIGHT TIME

2016 ◽  
Vol 78 (7-2) ◽  
Author(s):  
Nurul ‘Azizah Mukhlas ◽  
Nordiana Mashros ◽  
Othman Che Puan ◽  
Sitti Asmah Hassan ◽  
Norhidayah Abdul Hassan ◽  
...  
Keyword(s):  
Traffic Flow ◽  
Flow Characteristics ◽  
Mean Flow ◽  
Night Time ◽  
Lighting Condition ◽  
Adverse Weather ◽  
Traffic Flow Characteristics ◽  
Rural Highway ◽  
The Impact ◽  
The Relationship

Understanding traffic behavior for obtaining a smooth, safe and economical traffic operation requires a thorough knowledge of traffic flow parameters and their mutual relationships.Eventhough adverse weather can reduce traffic efficiencies, there are still questions to answer regarding the relationship between weather conditions and traffic flow at night. This paper presents an investigation of the rainfall effects to the traffic flow characteristics on atwo-lane rural highway during night time. The traffic data and corresponding rainfall data for uninterrupted road segment of Federal route 3 at Dungun, Terengganu were collected under road lighting condition during the north-east monsoon season. The effect of good weather condition, light rain, moderate rain and heavy rain conditions on speed, flow and density were quantified and compared. Results from the analysis indicate that mean speed, mean flow and mean density are reduced under various rainfall conditions. In general, the impact of good weather and various rainfall conditions on Greenshield’s fundamental traffic flow relationship have weak correlations except for the relationship between flow and density. The important points in the fundamental diagram derived from flow-density relationships indicated that critical density, maximum flow, critical speed, jam density and free flow speed of roadway all decrease as rainfall intensity increases. It can be concluded that traffic flow characteristics of two-lane rural highway in Terengganu are affected by rainfall conditions.

Stability analysis of car-following model on straight and curved roads considering the preceding vehicle’s velocity feedback control

2018 ◽  
Vol 32 (21) ◽  
pp. 1850238 ◽  
Author(s):  
Peng Tan ◽  
Di-Hua Sun ◽  
Dong Chen ◽  
Min Zhao ◽  
Tao Chen
Keyword(s):  
Feedback Control ◽  
Traffic Flow ◽  
Traffic Congestion ◽  
Velocity Feedback ◽  
Car Following ◽  
Car Following Model ◽  
Negative Feedback Control ◽  
The Stability ◽  
The Impact ◽  
Good Agreement

In order to reveal the impact of preceding vehicle’s velocity on traffic flow, an extended car-following model considering preceding vehicle’s velocity feedback control is proposed in this paper. The linear stability criterion of the new model is derived through control theory method and it shows that the feedback control signal impacts the stability of traffic flow. Numerical simulation results is in good agreement with the theoretical analysis, which prove that a smaller negative feedback control of the preceding vehicle’s velocity can enhance the stability of traffic flow, while a smaller positive feedback control of the preceding vehicle’s velocity can exacerbate traffic congestion. Moreover, the reaction coefficients of straight and curved road conditions also play an important role in the stability of traffic flow.

scholarly journals Research on Closed Residential Area Based on Balanced Distribution Theory

2018 ◽  
Vol 38 ◽  
pp. 03001
Author(s):  
Si Lan ◽  
Ni Fang ◽  
Hai Peng Lin ◽  
Shi Qi Ye
Keyword(s):  
Traffic Flow ◽  
Residential Area ◽  
Distribution Model ◽  
The Road ◽  
Resistance Model ◽  
Balanced Distribution ◽  
Residential Quarters ◽  
Opening And Closing ◽  
The Impact ◽  
The Relationship

With the promotion of the street system, residential quarters and units of the compound gradually open. In this paper, the relationship between traffic flow and traffic flow is established for external roads, and the road resistance model is established by internal roads. We propose a balanced distribution model from the two aspects of road opening conditions and traffic flow inside and outside the district, and quantitatively analyze the impact of the opening and closing on the surrounding roads. Finally, it puts forward feasible suggestions to improve the traffic situation and optimize the network structure.

scholarly journals Impact of Capacity Drop on Commuting Systems under Uncertainty

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Wenwei Zhang ◽  
Hui Zhao ◽  
Rui Jiang
Keyword(s):  
Traffic Congestion ◽  
Travel Cost ◽  
Peak Period ◽  
Travel Choice ◽  
Dispersion Degree ◽  
Proposed Model ◽  
The Mean ◽  
Capacity Drop ◽  
The Impact ◽  
The Relationship

This paper analyzes the impact of capacity drop on commuters’ travel choice behaviors under uncertainty. For clarity, we assume that the capacity drop is triggered by the queue forming at the bottleneck under the hypercongestion circumstances, and the stochasticity of the drop could not be neglected. Considering the uncertainty of travel time, we establish a bottleneck model with commuters choosing their departure time according to the mean travel cost. From the proposed model, analytical solutions are achieved and therefore several properties are presented, including monotonicity of travel cost and departure rate, and the relationship between dispersion degree and length of peak period. To alleviate traffic congestion at the bottleneck and avoid capacity drop, we design a time-varying toll scheme and a step toll scheme. Evolution of queue length in equilibrium is discussed based on the Laih model. Numerical examples are also presented to demonstrate the established model and the effectiveness of the proposed toll schemes.

scholarly journals The Impact of Truck Proportion on Traffic Safety Using Surrogate Safety Measures in China

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shengdi Chen ◽  
Shiwen Zhang ◽  
Yingying Xing ◽  
Jian Lu ◽  
Yichuan Peng ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Traffic Flow ◽  
Traffic Safety ◽  
Variation Coefficient ◽  
Support Vector ◽  
Safety Measures ◽  
Speed Variation ◽  
Surrogate Safety Measures ◽  
The Impact ◽  
The Relationship

The purpose of this study is to investigate the impact of the truck proportion on surrogate safety measures to explore the relationship between truck proportion and traffic safety. The relationship between truck proportion and traffic flow parameters was analyzed by correlation and partial correlation analysis, and the value of the 85th percentile speed minus the 15th percentile speed (85%V–15%V) and the speed variation coefficient were selected as surrogate safety measures to explore the impact of truck proportion on traffic status. The k-means algorithm and the support vector machine were employed to evaluate traffic status on a freeway under different truck proportions in different periods. The major results are that the relationship between truck proportion and the value of 85%V–15%V and the speed variation coefficient is consistent in different aggregation periods. With increasing truck proportion, the value of 85%V–15%V, as well as the speed variation coefficient, increases initially and then decreases. In addition, the traffic flow status tends to be dangerous when the truck proportion ranges from 0.4 to 0.6 and when the value of 85%V–15%V and the speed variation coefficient are above 42 km/h and 0.223, respectively. While the truck proportion is from 0.1 to 0.3 and from 0.7 to 0.9, the traffic flow is relatively safe on the condition that the value of 85%V–15%V and the speed variation coefficient were under 42 km/h and 0.223, respectively. Therefore, the relationship between truck proportion and traffic safety could be well revealed by two surrogate safety measures, that is, the value of 85%V–15%V and the speed variation coefficient. In addition, the k-means algorithm and the support vector machine can well reveal the impact of truck proportion on traffic safety in different periods. The findings of this study indicate a need for decreasing the disturbance of mixed traffic and the impact of the truck proportion on traffic safety status.

scholarly journals Analyzing the Impact of Trucks on Traffic Flow Based on an Improved Cellular Automaton Model

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Dewen Kong ◽  
Xiucheng Guo ◽  
Bo Yang ◽  
Dingxin Wu
Keyword(s):  
Cellular Automaton ◽  
Traffic Flow ◽  
Traffic Congestion ◽  
Traffic Volume ◽  
Cellular Automaton Model ◽  
Passenger Cars ◽  
Passenger Car ◽  
Car Following ◽  
Proposed Model ◽  
The Impact

This paper aims to analyze the impact of trucks on traffic flow and propose an improved cellular automaton model, which considers both the performance difference between passenger cars and trucks and the behaviour change of passenger cars under the impact of trucks. A questionnaire survey has been conducted to find out whether the impact of trucks exists and how the behaviour of passenger car drivers changes under the impact of trucks. The survey results confirm that the impact of trucks exists and indicate that passenger car drivers will enlarge the space gap, decelerate, and change lanes in advance when they are affected. Simulation results show that traffic volume is still affected by percentages of trucks in the congestion phase in the proposed model compared with traditional heterogeneous cellular automaton models. Traffic volume and speed decrease with the impact of trucks in the congestion phase. The impact of trucks can increase traffic congestion as it increases. However, it has different influences on the speed variance of passenger cars in different occupancies. In the proposed model, the relative relationship of the space gap between car-following-truck and car-following-car is changeable at a certain value of occupancy, which is related to the impact of trucks.

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