Lower speed limits hailed in SA CUTTING urban speed limits in South Australia to 50km/h has saved more than 100 lives and $1 billion in crash costs over the past decade. Marking the 10th year of the lower limit, Road Safety Minister Michael O'Brien says the change can now be declared a resounding success. "It has brought the significance of speed to the public's attention and actually led to lower speeds and less injuries on all roads, not just those that were changed to 50km/h," Mr O'Brien said on Friday. Over the past 10 years the state's road toll has dropped from 154 in 2002 to 94 in 2012, the 39 per cent fall the largest in any state or territory. Casualties have also fallen from 10,074 to 7473 while analysis by the University of Adelaide's Centre for Automotive Safety Research has found that average speeds have dropped and the number of drivers flouting the lower speed limit has halved.