BOSTON (CBS) – The Massachusetts Transportation Board has rejected the recommended upgrades that likely would have prevented last week’s Green Line crash, according to a report by The State House News Service.

The report says that board members turned down a $700 million proposal to add automatic crash prevention systems. The proposed upgrades would take nine years to complete and add similar safety features already in place on the Red, Blue, and Orange lines.

WBZ NewsRadio 1030′s Carl Stevens reports

While these upgrades would increase the Green Line’s safety, MBTA spokesman Joe Pesaturo says the system already has a good record.

“When you look at the national average around the country for light rail or trolley systems, the line is below the national average in the number of incidents and accidents that occur,” he said.

The cost would include the new “positive train control system” and necessary track upgrades that would prevent service slowdowns. The proposed finished product would have been able to accommodate more passengers, because it would have allowed adding a third car to trains.

The board decided to seek lower cost alternatives—including proximity sensors found on newer automobiles.

Last month’s Green Line accident, blamed on a drowsy operator, resulted in $500,000 in damages.

Transportation Secretary Richard Davey has advised engineering officials to submit a revised proposal.