Tolls are going up – that’s not negotiable. But the question of who gets squeezed the least is still up for debate.

The Maine Turnpike Authority says it must increase revenue by $20 million to cover its costs. It has already decided to increase the tolls at York and West Gardiner by 25 cents and to increase tolls at exchanges by 40 cents, beginning next February.

On Wednesday, the MTA outlined three scenarios for making up the rest of the revenue. Officials hope the public will look at the options and provide feedback at a series of scheduled forums before the MTA makes a final decision on Dec. 12. One forum is scheduled for 6 p.m. Wednesday, Dec. 3, at the Fireside Inn in Auburn.

Turnpike authority spokesman Dan Paradee said the budget gap is too large to be balanced by cuts alone.

“We’ve seen traffic stagnate, and at the same time, we’ve seen construction costs increasing by 55 percent,” he said.

The MTA has already tried to minimize its costs by cutting about $4 million in operating expenses from the 2009 budget and putting off all construction projects that can wait.

Lucien Gosselin, a member of the MTA board, said the board has worked hard to come up with scenarios that favor Maine drivers and distribute the costs as equitably as possible.

Each of the three proposals offers varying rate changes for different groups traveling on the turnpike.

The first scenario most favors Maine-based E-ZPass drivers by ensuring discounts on 61 percent of all turnpike routes. Participants in the MTA commuter plans would see their rates go up, but with the increase capped at 50 percent. Under this proposal, there would be a 50-cent increase at the New Gloucester toll, making it $1.75.

The second scenario most favors commuters. It is designed to balance the burden of commuters who travel through the more expensive tolls at York, New Gloucester and West Gardiner and commuters who do not. Rates for commuters traveling through the “mainline” tolls, such as those mentioned, would remain unchanged. Rates for commuters traveling the turnpike via “side” tolls – any toll that currently costs 60 cents – would see a proportional increase when those rates get raised to $1.

The third scenario would impose a 4 percent increase on tolls for commercial vehicles, above increases made for passenger vehicles. Commuters would see rates rise in proportion to toll changes.

MTA officials recognize there is one clear loser in all scenarios: the cash-paying driver.

“Those people who rely on and depend on the turnpike can get a significant break by using an (E-ZPass) and don’t have to pay the cash tolls,” Gosselin said. “Those who occasionally make use of the turnpike, say once a week or once a month and pay cash, they are going to find the toll increase a little bit steep.”

Turnpike toll rate proposals

A) Advantage: E-ZPass drivers who opened accounts in Maine

• Commuter rate increases capped at 50 percent.

• New Gloucester toll increases 50 cents to $1.75

• Maine-based E-ZPass drivers receive discounts for 61 percent of all turnpike routes.

B) Advantage: Enrolled commuters

• For commuters traveling through the most expensive MTA tolls, rates would remain unchanged. For commuters traveling through 60-cent tolls, rates would increase slightly.

• New Gloucester toll increases 50 cents to $1.75.

• Maine-based E-ZPass drivers receive discounts for 53 percent of all turnpike routes.

C) Disadvantage: Commercial drivers

• Commercial vehicle tolls would go up 4 percent beyond passenger car toll increases.

• Commuter rate increases capped at 50 percent.

• New Gloucester toll increases 25 cents to $1.50.

• Maine-based E-ZPass drivers receive discounts for 50 percent of all turnpike routes.