A program aimed at getting older, high-polluting vehicles off the state’s roads has hit a speed bump.

Because the Department of Environmental Protection was unsure that it could make emergency changes to regulations based on new legislation, the agency decided to delay implementation for a second time.

The Board of Environmental Protection was slated to vote on the amended program at its meeting this Thursday, so that people who scrap pre-1987 cars and buy newer, low-emissions vehicles could begin collecting vouchers from the state next month.

Instead, the program won’t get going until this fall, said Ron Severance, who oversees the high-pollution vehicle retirement program for the DEP.

Initially, the agency hoped to start offering vouchers last fall, but none of the state’s automobile recyclers agreed to participate. They said it would cost them money to drain and dispose of fluids from the old cars, something they weren’t willing to do for free.

So, the Legislature amended the law to offer recyclers up to $350 per car. It also expanded the program to include junkyards and automobile graveyards, which don’t have to comply with as stringent environmental laws as recyclers. They also are eligible for the $350.

Because the DEP has only $110,000 available for the program, the changes mean that now there is enough money to take only 66 cars off the road. Before the payments to the scrappers, there were enough funds to take 88 cars off the road.

“We were hoping, from the citizen’s perspective, to start soon rather than later,” Severance said Tuesday.

But, he said, legally the most recent legislation does not provide the department with enough flexibility to make the changes on an emergency basis. Instead, they have to wait until 90 days after the Legislature adjourns.

The program offers between $1,000 and $2,500 to people who provide evidence that their pre-1987 car or truck was scrapped, and they purchased a certified low-emissions vehicle made after 1996.

To date, more than 1,000 people have signed up for vouchers. The department will continue to maintain that list while waiting for the program to begin.