Studies from A. Briz-Redon and Co-Authors Have Provided New Information about Accident Research (Investigation of the consequences of the modifiable areal unit problem in macroscopic traffic safety analysis: A case study accounting for scale …)

2019 SEP 27 (NewsRx) -- By a News Reporter-Staff News Editor at Insurance Daily News -- New research on Accident Research is the subject of a report. According to news reporting originating in Burjassot, Spain, by NewsRx journalists, research stated, “Traffic safety analysis at the macroscopic level usually relies on previously defined areal traffic analysis zones (TAZs) that are used as the units of investigation. Hence, statistical inference is made on the basis of such units, implying that the consideration of a certain TAZ configuration may influence the results and conclusions achieved.”

The news reporters obtained a quote from the research, “Regarding this, the modifiable areal unit problem (MAUP) is a well-known issue in the field of spatial statistics, which refers to the effects that arise in statistical properties and estimations when there is a change in areal units of analysis. In this paper, the consequences of MAUP have been investigated through a dataset of traffic crashes that occurred in Valencia within the years 2014 and 2015 and two common statistical models: a conditional autoregressive model and a geographically weighted regression. In the absence of an established TAZ scheme for the city, four classes of basic spatial units (BSUs) were considered: census tracts, hexagonal units and two types with construction based on the structure of main roads and intersections of the city. Each of these BSU types was specified at different levels of spatial aggregation. The main research objective was to investigate the final effects that changes in BSU type and scale have on model parameter estimations, but also the specific alterations that MAUP causes to data in terms of the distributional characteristics of the response, multicollinearity among the covariates and covariates’ spatial autocorrelation. The results showed the presence and severity of MAUP for the dataset and area that were analysed. Although effects from scale variations were more moderate, changing the BSU type affected the results severely. The joint use of hexagonal units and a conditional autoregressive model achieved the best performance among all the possibilities explored, but the choice of a proper BSU unit should rely on more factors. Despite MAUP effects, educational centres showed a consistent (and negative) association with traffic crashes, a fact possibly related to their distribution across the whole city.”

According to the news reporters, the research concluded: “Other covariates revealed a positive correlation with crash counts, but these findings were more uncertain given the discrepancies found at different scales and zonings.”

For more information on this research see: Investigation of the consequences of the modifiable areal unit problem in macroscopic traffic safety analysis: A case study accounting for scale and zoning. Accident, 2019;132():105276. (Elsevier - www.elsevier.com; Accident - http://www.journals.elsevier.com/accident-and-emergency-nursing/)

Our news correspondents report that additional information may be obtained by contacting A. Briz-Redon, Statistics and Operations Research, University of Valencia, C, Dr Moliner, 50, Burjassot 46100, Spain. Additional authors for this research include F. Martinez-Ruiz and F. Montes.

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