All newly manufactured vehicles to be sold in the U.S. are required as of Tuesday to have backup cameras equipped as a standard feature. Advocates for the rule, which was mandated by the National Highway Transportation Safety Agency in 2014, hope today’s milestone will lead to fewer instances of drivers backing into people due to a lack of visibility. “This day is so important because we don’t have a choice” when it comes to children’s safety around cars, said Janette Fennell, founder and president of KidsAndCars.org, an advocacy group that works to prevent accidents involving children and motor vehicles. “This...