Title: The methodology and initial findings for the Road Accident In Depth Studies (RAIDS) Programme: RAIDS Phase 1 Report

Organisation: TRL
Date uploaded: 22nd March 2017
Date published/launched: February 2017

This report provides an overview of the Road Accident In Depth Studies (RAIDS) programme and describes the aims of the in-depth data collection, the sampling strategy, and a high level overview of the data collected during the first phase.

It should be recognised that RAIDS is an evidence base – a resource that can be used to investigate and answer a wide range of research questions.

The RAIDS database is already being successfully used by a range of research projects, each with specific research questions.

As data collection continues into a second phase, sample sizes will increase, enabling research questions to be answered more robustly and allowing improvements that ensure that the data collected are able to address tomorrow’s research questions.

Among the main conclusions of the report are:

• Phase 1 of the RAIDS programme resulted in the collection of 1,255 cases (630 on-scene, 373 retrospective car, and 252 retrospective large vehicle) being collected from two discrete sampling regions.

• If only the injurious RAIDS cases are considered, fatal collisions are overrepresented by a factor of 11.2, serious by 2.6, with slight collisions being underrepresented by a factor of 0.59, compared with data from RRCGB 2014 (The Department for Transport, 2015).

• The RAIDS sample is comparable to the national sample with respect to the distribution of vehicle types. In both cases, passenger cars predominate, representing over 70% of vehicles. However, RAIDS contains greater proportions of goods vehicles and lesser proportions of Vulnerable Road Users compared to the national data.

• Cars dominate the RAIDS sample (over 71% of vehicles). For all KSI collisions, head-on (17.99%), loss of control (14.96%) and rear end (11.74%) are the most frequently occurring collision types.

• Car casualties dominate the RAIDS sample, with 25-34 year olds, followed by 16-24 and 35-44 being the most frequent casualty age groups. Other vehicle types exhibit different age patterns which most likely reflect exposure, although the sample size is small. Overall, male casualties comprise more than 62% of the sample.

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