Freeway Multisensor Data Fusion Approach Integrating Data from Cellphone Probes and Fixed Sensors

Abstract

Freeway traffic state information from multiple sources provides sufficient support to the traffic surveillance but also brings challenges. This paper made an investigation into the fusion of a new data combination from cellular handoff probe system and microwave sensors. And a fusion method based on the neural network technique was proposed. To identify the factors influencing the accuracy of fusion results, we analyzed the sensitivity of those factors by changing the inputs of neural-network-based fusion model. The results showed that handoff link length and sample size were identified as the most influential parameters to the precision of fusion. Then, the effectiveness and capability of proposed fusion method under various traffic conditions were evaluated. And a comparative analysis between the proposed method and other fusion approaches was conducted. The results of simulation test and evaluation showed that the fusion method could complement the drawback of each collection method, improve the overall estimation accuracy, adapt to the variable traffic condition (free flow or incident state), suit the fusion of data from cellphone probes and fixed sensors, and outperform other fusion methods.

A data-driven study on the sample size of cellular handoff probe system

“…This finding is consistent with some existing research works. 10,18,19 The PPMCC of TSS is larger than that of ASS, which indicates that the negative correlation becomes stronger with the growth of statistical time.…”

“…There are several kinds of cell phone probe-based techniques, that is, assisted global positioning system (A-GPS) method, angle of arrival (AOA) technique, time difference of arrival (TDOA) technique, handoffbased method, and cell phone activity data-based method. 1,[7][8][9][10] Among them, the cellular handoff probe system (CHPS) is extensively studied and tested for the collection of traffic speeds. A handoff event is one kind of cell phone communication records.…”

“…Based on the simulation or field experiment, more investigation was conducted to study the factors affecting the sample size of CHPS, such as the length of handoff links and traffic volume. 10 However, numerical field test was conducted to explain the influence of traffic flow, the call duration, and the length of handoff link on sample size. 19 However, either the simulation or field experiments could not repeat the complexity of CHPS in the real world.…”

“…Use handoff probe system to track a vehicle. 10 and t n and t n + 1 are handoff timestamps as shown in Figure 1.…”

Online Traffic Condition Evaluation Method for Connected Vehicles Based on Multisource Data Fusion

“…Guo et al proved the urban road traffic conditions can be analyzed with traffic data of coil detector by improved fuzzy clustering method [14]. He et al improved a fusion method with new data collected from mobile phone and microwave sensors, providing enough data for traffic analysis [15].…”