Speeding is the top contributing factor in serious casualty (fatality and serious injury) crashes in Tasmania. Half the serious casualties are in 100 km/h or 110km/h speed zones. Road Safety Advisory Council market research found 32 percent of drivers thought it was “generally acceptable” to travel between five and 10 kilometres over the limit and 13 percent thought it was okay to drive more than 10 km/h over the limit “on the open road if you were an experienced driver”.