The government said capping speeds for large vehicles will reduce the 1,115 fatal crashes involving heavy trucks that occur each year and save $1 billion in fuel costs. The proposal from the National Highway Traffic Safety Administration and Federal Motor Carrier Safety Administration is subject to public comment before becoming final. The group was founded by Atlanta financial adviser Scott Owings and his wife Susan, whose son Cullum was killed by a speeding tractor-trailer during a trip back to school in Virginia after Thanksgiving in 2002. The government agencies involved will take public comment for 60 days, then determine the final limit and decide if the regulation should be put in place. [...] Norita Taylor, spokeswoman for the 157,000-member Owner Operator Independent Drivers Association, said her group has opposed the speed limiters because they create dangerous interactions between vehicles as faster cars slow down for trucks.