LAPLACE �“ State Department of Transportation and Development officials green-lighted plans this week to replace and improve traffic signals on Airline Highway across three parishes, said a spokesman for the department.

Louisiana will pay about $4.6 million to Jack B. Harper Contractors Inc. to replace about 30 traffic lights at intersections in Jefferson, St. Charles and St. John Parishes, according to DOTD spokeswoman Amber Hebert. Hebert said the Mandeville firm was the lowest bidder among four other companies who submitted proposals for the project last week.

Hebert said once the contract is reviewed and accepted, work could begin within two to three months. She said the job should take about nine months to complete, barring any delays from severe weather. The intersections receiving the upgraded signals stretch across 21 _ miles of the heavily traveled thoroughfare, which is also used as an evacuation route during hurricane season. Hebert said the new lights would be mounted on poles running across the roadway instead of hung from cables, making them less likely to be blown down in a storm.

Hebert said the signals would also feature video cameras and detection loops to allow for remote adjustment of the timing of the signals.

“The signals would be tied in to our new command center that is going up at the Orleans Parish line,” said Hebert. “Monitors at the center could take control of the lights to lengthen or shorten them based on traffic flow.”

The work is not expected to cause any severe traffic delays, Hebert said.