Lateral Protection Devices (LPDs) fitted to trucks are an effective way to lessen the severity of a crash with a pedestrian or cyclist. According to Knight et. al (2005) the effectiveness of LPDs in preventing fatalities in crashes with the side of large trucks range from 50 to 74 per cent for bicyclists and 17 to 27 per cent for pedestrians. 

Research: Knight et. al (2005) Integrated Safety Guards and Spray Suppression – Final Summary Report
Video source: Volpe Center 

Further research on this topic: