Antilock braking system effectiveness in prevention of road traffic crashes in Iran

Anti‐lock Brake System (ABS) helps the equipped vehicles to stop under heavy
braking, in a shorter distance and with a better control of direction. It was expected that this
technology will reduce the rate of fatal road traffic crashes (RTC); however, the outcome was
controversial in the real world.
Aim: The aim of this study was to compare the claimed annual incidence and financial loss due
to RTC in ABS vs. non‐ABS personal vehicles in Iran.
Methods: A telephone survey among drivers of two similar models of personal vehicles was
arranged. The studied models were of the same brand and type; but only one of them was
equipped with ABS. The number of RTCs, subsequent financial loss, and drivers’ knowledge
and perception about ABS were sought. The sample consisted of drivers of 1232 ABS and 3123
non‐ABS vehicles.
Results: The mean financial loss due to reported RTCs was $987.9 ±$1547.3 US Dollars. They
were similar in both study groups. The incidence of RTC with another vehicle due to brake
failure, was 50.3 (42.9‐58.5) for 1000 non ABS vehicle‐years and 30.0 (21.2‐41.2) for 1000 ABS
equipped vehicle‐years. The difference was statistically significant after adjustment for the driver
and vehicle's age and the daily driving time. The attributable risk of RTC for non‐ABS vehicles
was 20/1000 vehicles and the excess fraction was 39.8%. While 61.1% of ABS vehicle drivers
reported situations in which they believed the ABS had prevented a crash, 44.1% of them did not
know how to use ABS efficiently.
Conclusions: