The validity of the TR safety observation method on building construction.

The safety inspectors carried out monitoring visits to 305 building construction sites, and the results were compared with the accident figures of the same sites. The average number of observations per site was 144, and the observed safety aspects were: working habits, scaffolding and ladders, machines and equipment, protection against falling, lighting and electricity, and order and tidiness. Each item was scored as 'correct' if it met the safety standards, otherwise the item was scored as 'not correct'. The safety index was calculated as a percentage of the 'correct' items related to all the observed items. Only some hours of training were needed for making reliable observations, when the observers already knew the safety standards. Also the validity proved to be good. The sites were grouped according to the observed safety index in order to limit the huge random variation in the accident rates of single sites. There was a significant correlation between the observed safety index and the accident rate of the site groups. The sites with the lowest observed safety index had, on average, a three times higher accident rate than the sites with the highest safety index. The method is used by the site personnel as an internal weekly safety inspection and feedback tool. The state safety inspectors use the method as a means of objective feedback for the companies.