The state plans to erect more than 20 miles of additional cable median barriers along Interstate 10 to prevent crossover accidents, including one near a site where five people were killed in March, officials said Tuesday.

“This project will save lives,” said Sherri LeBas, secretary for the state Department of Transportation and Development.

The barriers are designed to deflect vehicles that enter the median, keeping them from crossing over into oncoming traffic.

The cost is $2.7 million, all from federal safety funds.

The additions will bring the total of cable median barriers on I-10 and I-12 in Louisiana to nearly 81 miles.

The new sites are:

e_SBlt In East Baton Rouge Parish, one mile from the Highland Road exit on I-10 to the Ascension Parish line.

e_SBlt In Ascension Parish, one mile south from the East Baton Rouge Parish line, 3.5 miles south from La. 73 and 6.5 miles from La. 22 to the St. James Parish line.

e_SBlt From the existing cable barrier in St. James and St. John parishes, 4.7 miles to the Reserve Relief Canal Bridge, then 3.3 miles to the Bonnet Carré Spillway.

• In Jefferson Parish, 2.5 miles from the St. Charles Parish line to the Veterans Boulevard interchange.

Earlier this year, a mother, her three children and a second adult were killed on I-10 near Highland Road when a pickup truck crossed the median as it spun clockwise and struck a car they were riding in head on.

In 2008, Grace Gary, 8, was killed on I-10 when she and her Baton Rouge family were returning from New Orleans on Palm Sunday.

An eastbound pickup truck crossed the I-10 median without braking and slammed into the Garys’ Honda Odyssey.

Mona Gary, who is Grace’s mother, was at Tuesday’s news conference and praised plans for the additional cable barriers.

She said her family recently traveled through St. James Parish and was heartened to see cable median barriers on I-10.

“There was a sense of security,” Gary said.

She said the additional barriers lessen chances that other families will experience what hers did.

“I would just like to thank you so much,” Gary said of plans for the additional barriers.

John LeBlanc, executive director of the Louisiana Highway Safety Commission, and Col. Mike Edmonson, superintendent of Louisiana State Police, said the barriers are highly effective in trimming highway accidents.

Federal dollars for the cable barriers stem in part from the state’s high rate of fatal highway accidents where cars and trucks left the roadway, said Mary Stringfellow, an official of the Federal Highway Administration/Louisiana division.

LeBas said installation of the cable barriers will start next month and should be finished by spring.

Barriers will start going up in Jefferson Parish and move west toward Baton Rouge.

The cable costs about $200,000 per mile.

Sites are picked from a state analysis of vehicles crossing the median per mile, transportation officials said.

Cable median barriers are already up on I-12 through St. Tammany Parish, 32 miles; I-10 in St. James Parish, 6.8 miles; I-12 in Tangipahoa Parish; and I-10 from the St. John Parish line to the Hope Canal, 19.5 miles.