01.12.2019 | Research | Ausgabe 1/2019 Open Access

# Spatial analysis of traffic accidents based on WaveCluster and vehicle communication system data

## 1 Introduction

## 2 Data sources and overall analysis

### 2.1 Data sources

### 2.2 Overall analysis

## 3 The analysis method based on WaveCluster

### 3.1 Wavelet analysis of time series

_{f}(a, b) is the wavelet transform coefficient, f(kΔt) is a discrete signal, a is the scaling scale, b is the translation parameter, \( \psi \left(\frac{k\varDelta t}{a}\right) \) is the basis wavelet function, and \( \overline{\psi}\left(\frac{k\varDelta t-b}{a}\right) \) is the complex conjugate function. In this study, the most important thing is to obtain the wavelet coefficients from the wavelet transform equation, use these coefficients to analyze the time-frequency variation characteristics of the time series, and conduct clustering analysis based on these coefficients to obtain the spatial differentiation pattern of traffic accidents.

### 3.2 K-means clustering of time series wavelet decomposition

Traffic police brigade | 201,501 | 201,502 | 201,503 |
---|---|---|---|

Xidan traffic police brigade | 0 | 2 | 2 |

East traffic police brigade | 0 | 0 | 1 |

_{ij}between sample i and and all samples of other cluster C

_{j}is called the dissimilarity between sample I and cluster C

_{j}. Defined as the sample I, there is no similarity between clusters, b = min {b

_{i1}, b

_{i2},... b

_{ik}}. The silhouette coefficient s is the mean value of s(i) of all samples. The closer the s is to 1, the better the sample clustering effect is. Therefore, we can try to set different k values to calculate the corresponding s and select the k value closest to 1 to get a more ideal cluster number.

## 4 Analysis of experimental results

### 4.1 Spatial differentiation of traffic accidents based on WaveCluster

k
| 3 | 4 | 5 | 6 | 7 | 8 |

s
| 0.691 | 0.732 | 0.864 | 0.853 | 0.847 | 0.793 |

### 4.2 Spatial distribution characteristics of traffic accidents

### 4.3 Analysis of accident causes based on data of vehicle information system

Types | Vehicle communication system |
---|---|

Communication | Mobile phones, smart phones, car electronic communication stations, etc. |

Navigation | GPS navigator, advanced traveler information system, etc. |

Entertainment | DVD, CD, TV, etc. |

Working | Car computer, PDA, etc. |

Controlling | In-vehicle facility switch and adjustment control, etc. |