TRENTON, N.J. — New school buses in New Jersey will have to be equipped with exterior object-detecting sensors under a bill signed into law on Tuesday.

The bill was dubbed "Abigail's Law" for Abigail Kuberiet, a 1-year-old girl who was killed in 2003 at the front of a stopped school bus in South Plainfield, New Jersey. Sponsors of the bill said that the school bus driver in that incident couldn’t see the girl from the driver's seat.

"The use of available technology will facilitate safe driving and prevent fatal accidents," said Assemblyman Patrick Diegnan, a primary sponsor of the bill. "When an alarm sounds if a child is in the vicinity of the bus, the operator will immediately be made aware of the situation and will not move forward, and a life will be saved."

Gov. Chris Christie gave final approval to the legislation on Tuesday after it passed both houses of the state Legislature by unanimous votes — notable considering that “Abigail’s Law” had been introduced in previous legislative sessions but had not passed.

The required sensors will alert the school bus driver if there are children in front or in back of the bus. The devices will have to conform to regulations approved by the State Board of Education, in consultation with the New Jersey Motor Vehicle Commission.

The mandate goes into effect for newly manufactured school buses in 180 days from the bill’s approval. A fiscal estimate on the bill indicated that the cost per school bus may range from about $900 to $1,300, depending on the configuration of the sensors.

"Regardless of how much we teach the importance of school bus safety to children, accidents can happen in just the blink of an eye," said Assemblywoman Gabriela Mosquera, another primary sponsor of the bill. "Putting sensors on buses simply is an additional step that can help reduce the likelihood of an accident and keep children in New Jersey safe."