An estimated 23,000 regular Maine Turnpike E-ZPass users received letters last week alerting them that their commuter plan will be replaced by a volume based discount plan beginning Nov 1.

That change was part of a series of recently approved toll hikes that Maine Turnpike Authority officials said were needed to cover operating expenses, upkeep of the highway and pay off past debt.

Although the shift away from the commuter plan program is expected to negatively affect only about 2,000 customers, MTA spokesman Dan Morin said, those customers are responding to the letter with outrage.

Morin said the authority has received numerous calls and emails since the letter was sent. Comments also have flooded into the Maine Turnpike Authority’s Facebook page in the last week.

Joe Thibeault uploaded a picture of his vehicle with the words “The MTA are thieves,” painted on the back window.

Micah Malloy wrote: “I drive from Auburn to Augusta for work every weekday and it used to cost me $63.75 per quarter to commute using the turnpike. Now starting November 1st it will cost me, with my discount, $40 per month.”

Shana Therrien is in the same boat.

“I was paying about $56 every three months for my Commuter Plan in which I travel five days a week from Exit 32 to 44. I’m now looking at $45 a month,” she wrote. “And if I opt to skip out on the 295 toll and take Exit 45, I then wouldn’t be making enough trips to garner the 50 [percent] discount.”

Morin said the change in the commuter program was part of the MTA’s plan all along but acknowledged that it probably did not generate as much attention as some of the other changes.

“We appreciate the frustration of those who are seeing rates go up , but we didn’t target those users for a specific increase,” Morin said. “It was developed to arrive at a fair and equitable toll rate for all users.”

The turnpike authority proposed raising tolls and making changes to the E-ZPass program earlier this summer and spent several weeks discussing various options with the public.

The MTA’s board voted on the following changes in August:

The per-mile rate for all E-ZPass users is set to increase from 6.7 cents to 7.7 cents. Users who travels more than 30 trips per month will receive a 10-percent discount. Users who travel more than 40 trips will get a 20-percent discount. The biggest discount of 50 percent will affect users who travel on the turnpike more than 70 times each month.

Individual toll increases also were approved. The York toll will increase from $2 to $3; the New Gloucester toll will increase from $1.75 to $2.25; the West Gardiner exchange will increase from $1.25 to $1.75; and the Wells northbound and Gray southbound tolls will jump from $1 to $1.50.