5,561 research outputs found
DxNAT - Deep Neural Networks for Explaining Non-Recurring Traffic Congestion
Non-recurring traffic congestion is caused by temporary disruptions, such as
accidents, sports games, adverse weather, etc. We use data related to real-time
traffic speed, jam factors (a traffic congestion indicator), and events
collected over a year from Nashville, TN to train a multi-layered deep neural
network. The traffic dataset contains over 900 million data records. The
network is thereafter used to classify the real-time data and identify
anomalous operations. Compared with traditional approaches of using statistical
or machine learning techniques, our model reaches an accuracy of 98.73 percent
when identifying traffic congestion caused by football games. Our approach
first encodes the traffic across a region as a scaled image. After that the
image data from different timestamps is fused with event- and time-related
data. Then a crossover operator is used as a data augmentation method to
generate training datasets with more balanced classes. Finally, we use the
receiver operating characteristic (ROC) analysis to tune the sensitivity of the
classifier. We present the analysis of the training time and the inference time
separately
High-Resolution Road Vehicle Collision Prediction for the City of Montreal
Road accidents are an important issue of our modern societies, responsible
for millions of deaths and injuries every year in the world. In Quebec only, in
2018, road accidents are responsible for 359 deaths and 33 thousands of
injuries. In this paper, we show how one can leverage open datasets of a city
like Montreal, Canada, to create high-resolution accident prediction models,
using big data analytics. Compared to other studies in road accident
prediction, we have a much higher prediction resolution, i.e., our models
predict the occurrence of an accident within an hour, on road segments defined
by intersections. Such models could be used in the context of road accident
prevention, but also to identify key factors that can lead to a road accident,
and consequently, help elaborate new policies.
We tested various machine learning methods to deal with the severe class
imbalance inherent to accident prediction problems. In particular, we
implemented the Balanced Random Forest algorithm, a variant of the Random
Forest machine learning algorithm in Apache Spark. Interestingly, we found that
in our case, Balanced Random Forest does not perform significantly better than
Random Forest.
Experimental results show that 85% of road vehicle collisions are detected by
our model with a false positive rate of 13%. The examples identified as
positive are likely to correspond to high-risk situations. In addition, we
identify the most important predictors of vehicle collisions for the area of
Montreal: the count of accidents on the same road segment during previous
years, the temperature, the day of the year, the hour and the visibility
RiskOracle: A Minute-level Citywide Traffic Accident Forecasting Framework
Real-time traffic accident forecasting is increasingly important for public
safety and urban management (e.g., real-time safe route planning and emergency
response deployment). Previous works on accident forecasting are often
performed on hour levels, utilizing existed neural networks with static
region-wise correlations taken into account. However, it is still challenging
when the granularity of forecasting step improves as the highly dynamic nature
of road network and inherent rareness of accident records in one training
sample, which leads to biased results and zero-inflated issue. In this work, we
propose a novel framework RiskOracle, to improve the prediction granularity to
minute levels. Specifically, we first transform the zero-risk values in labels
to fit the training network. Then, we propose the Differential Time-varying
Graph neural network (DTGN) to capture the immediate changes of traffic status
and dynamic inter-subregion correlations. Furthermore, we adopt multi-task and
region selection schemes to highlight citywide most-likely accident subregions,
bridging the gap between biased risk values and sporadic accident distribution.
Extensive experiments on two real-world datasets demonstrate the effectiveness
and scalability of our RiskOracle framework.Comment: 8 pages, 4 figures. Conference paper accepted by AAAI 202
Accident Risk Prediction based on Heterogeneous Sparse Data: New Dataset and Insights
Reducing traffic accidents is an important public safety challenge,
therefore, accident analysis and prediction has been a topic of much research
over the past few decades. Using small-scale datasets with limited coverage,
being dependent on extensive set of data, and being not applicable for
real-time purposes are the important shortcomings of the existing studies. To
address these challenges, we propose a new solution for real-time traffic
accident prediction using easy-to-obtain, but sparse data. Our solution relies
on a deep-neural-network model (which we have named DAP, for Deep Accident
Prediction); which utilizes a variety of data attributes such as traffic
events, weather data, points-of-interest, and time. DAP incorporates multiple
components including a recurrent (for time-sensitive data), a fully connected
(for time-insensitive data), and a trainable embedding component (to capture
spatial heterogeneity). To fill the data gap, we have - through a comprehensive
process of data collection, integration, and augmentation - created a
large-scale publicly available database of accident information named
US-Accidents. By employing the US-Accidents dataset and through an extensive
set of experiments across several large cities, we have evaluated our proposal
against several baselines. Our analysis and results show significant
improvements to predict rare accident events. Further, we have shown the impact
of traffic information, time, and points-of-interest data for real-time
accident prediction.Comment: In Proceedings of the 27th ACM SIGSPATIAL, International Conference
on Advances in Geographic Information Systems (2019). arXiv admin note:
substantial text overlap with arXiv:1906.0540
Spatiotemporal Graph Neural Networks with Uncertainty Quantification for Traffic Incident Risk Prediction
Predicting traffic incident risks at granular spatiotemporal levels is
challenging. The datasets predominantly feature zero values, indicating no
incidents, with sporadic high-risk values for severe incidents. Notably, a
majority of current models, especially deep learning methods, focus solely on
estimating risk values, overlooking the uncertainties arising from the
inherently unpredictable nature of incidents. To tackle this challenge, we
introduce the Spatiotemporal Zero-Inflated Tweedie Graph Neural Networks
(STZITD-GNNs). Our model merges the reliability of traditional statistical
models with the flexibility of graph neural networks, aiming to precisely
quantify uncertainties associated with road-level traffic incident risks. This
model strategically employs a compound model from the Tweedie family, as a
Poisson distribution to model risk frequency and a Gamma distribution to
account for incident severity. Furthermore, a zero-inflated component helps to
identify the non-incident risk scenarios. As a result, the STZITD-GNNs
effectively capture the dataset's skewed distribution, placing emphasis on
infrequent but impactful severe incidents. Empirical tests using real-world
traffic data from London, UK, demonstrate that our model excels beyond current
benchmarks. The forte of STZITD-GNN resides not only in its accuracy but also
in its adeptness at curtailing uncertainties, delivering robust predictions
over short (7 days) and extended (14 days) timeframes
Big Data for Traffic Estimation and Prediction: A Survey of Data and Tools
Big data has been used widely in many areas including the transportation
industry. Using various data sources, traffic states can be well estimated and
further predicted for improving the overall operation efficiency. Combined with
this trend, this study presents an up-to-date survey of open data and big data
tools used for traffic estimation and prediction. Different data types are
categorized and the off-the-shelf tools are introduced. To further promote the
use of big data for traffic estimation and prediction tasks, challenges and
future directions are given for future studies
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