New York's Transportation Department says it's addressing some safety concerns on a stretch of highway where an accident killed seven people.

Commissioner Joan McDonald says new concrete barriers will be installed on the outside travel lane on three Bronx River Parkway viaducts in New York City.

One of those viaducts is 60 feet over the Bronx Zoo, where an SUV landed on Sunday, killing seven members of a Bronx family.

Police said the SUV hit the median, crossed three lanes and hit a 2-foot-high concrete curb. The SUV then flew over a 4-foot guardrail and plummeted to the zoo below, killing the driver and six passengers on impact.

McDonald says crews started working Wednesday morning on signs and striping on the highway.