An accelerating pace of domestic oil and natural gas production has strained existing pipeline capacity, prompting some energy companies to turn to rail to get natural resources to their customers.
Moniz told the Capital New York news agency the "handful of train accidents" involving railcars carrying crude oil have been "quite troubling."
U.S. safety regulators said older DOT-111 cars, some of which were involved in recent derailments, may be more vulnerable to leaks or explosions than other types of rail cars. In January, the federal government issued a safety alert saying the type of crude oil in the Bakken reserve area in North Dakota may be more flammable than other grades.
Moniz said in an interview published Wednesday using pipelines was "probably" the better option in terms of cost, safety and emissions.
"What we probably need is more of a pipeline infrastructure and to diminish the need for rail transport over time," he said.