A one-way trip from New Haven to the New York border could cost just over $6 during rush hour.

The same trip along the scenic Merritt Parkway would run $5 — a slight savings but not much.

That could be the cost of driving on state highways if the General Assembly authorizes electronic tolls endorsed by Gov. Dannel P. Malloy and the legislature’s majority Democratic leaders.

A study previously commissioned by the state offers a detailed look at tolling on I-95, the Merritt Parkway and I-84. The 297 pages suggest potential toll prices, gantry locations and various scenarios to scan license plates and charge drivers for miles they travel. A gantry is a bridge-like structure over the highway that would use electronic technology to scan license plates and charge vehicles driving under it.

The prices are only projections, but they give a sense of what tolling could cost commuters and the average driver.

“The time has come for the state to implement tolling,” said Jim Gildea, president of the Connecticut Commuter Rail Council.

“Connecticut’s transportation system is in sore need of critical investment, in terms of both structural requirements and service needs, and finding funding sources to meet these demands is an absolute must,” Gildea said.

With revenue estimates around $800 million a year, tolls are an attractive option for lawmakers looking for big money — $100 billion over the next 30 years — to improve the state’s infrastructure and reduce congestion, especially in Fairfield County, where many believe traffic is costing jobs and economic development.

While the likelihood of highway tolls grew with Malloy’s backing and the endorsement of Democratic leaders, most Republican lawmakers remain opposed. The GOP, with the help of a few Democrats, has shown it can block bills pushed by the majority.

J.R. Romano, the state Republican party chairman, said state residents already pay the third highest gas tax in the nation and don’t need the additional burden of tolls.

He said Malloy wants to increase the gas tax by 7 cents over the next four years.

“Look at families who are struggling just to break even,” Romano said. “When coupled with the gas tax, that’s the fundamental problem. They would pay $2,200 more a year in gas taxes and now a toll on top of that.”

The 2016 study by CDM Smith paints a picture of a state highway system dominated by electronic gantries to scan plates and charge tolls.

Under one scenario outlined in the CDM Smith report, 12 gantries would be placed on I-95, beginning in West Haven and ending at the New York State line in Greenwich. Every time a vehicle passed under a gantry, a fee would be charged.

Motorists on the Merritt Parkway would pass under a gauntlet of 10 gantries, beginning at New Haven and ending at the state line, the CDM Smith study shows. Every gantry would mean another charge.

The study did not detail specific plans for I-84, but noted tolls are likely from the New York border to Hartford.

CDM Smith projected prices at 50 cents per gantry during peak times and 35 cents during off peak times.

Another scenario set the peak price at 80 cents and off peak at 56 cents per gantry. Under that pricing, a peak time one-way trip from New Haven to the New York border would cost $9.60 cents.

The consultant estimated it would cost $35 million to install a series of gantries along I-95 and $50 million if they are installed on the Merritt Parkway. Those estimates don’t include operating and other costs.

Romano estimated that at 50 cents per gantry, a commuter traveling from New Haven to Fairfield five days a week during rush hour would pay $1,300 a year.

“That’s not good,” Romano noted. “This is already an expensive state to live in.”

The study offers a variety of options, ranging from constant tolling to congestion pricing, which means only charging tolls during peak rush hour times or raising prices during those periods.

Alternatives offered by the study include installing tolls and widening I-95 between Greenwich to Bridgeport and widening and tolling parts of the Merritt Parkway from Greenwich to New Haven.

Some scenarios change pricing and alter the frequency of tolling, exempt state residents from tolls or charge them a lesser fee. Other options toll state roads, such as Rt. 8 from Bridgeport to Waterbury.

The Governor’s Transportation Finance Panel several years ago estimated that out-of-state drivers would provide 30 percent of the state’s toll revenue.

Opposition to tolling will be difficult to overcome if there is a serious push for highway fees. Democrats hold a slim advantage in the House and they are tied with the GOP in the Senate, although Lt. Gov. Nancy Wyman can break a deadlock.

The GOP showed its muscle last year when, with the help of a handful of Democrats, the party adopted its state budget and blocked Malloy’s spending proposal

“This is a mileage tax,” State Senate Minority Leader Len Fasano, R-North Haven, said during a Facebook broadcast last week.

“If you go out of your town you are going to hit a toll,” Fasano said. “This would be hoops every mile or every five miles. It’s a really bad idea. It’s only a couple of bucks but by the end of the year it adds up to significant dollars.”

Instead of authorizing tolls this year, Fasano said the state should conduct a detailed study of the idea.

“We should see the plan and all of us decide if it’s a good idea,” Fasano said. “Let’s do a plan, study it and then make an intelligent decision.”

While another study might be attractive to lawmakers facing re-election this fall, the state paid for toll and congestion studies in 2015 and 2016, and the Governor’s Transportation Finance Panel recommended tolls as one of numerous ways to fund infrastructure improvements.

Patrick Sasser, a partner in a Stamford trucking company, said the last thing the state needs is tolls.

“We need the governor and elected state officials to know that we are being taxed to death and that is not the solution to our financial troubles,” Sasser said.

“We are asking them to find different ways to save money and cut spending,” Sasser added. “These tolls and increased gas taxes will fall on the backs of the already struggling working class in Connecticut, and we simply can’t afford that.”

Sasser is organizing a rally on Feb. 17 from 11 a.m. to 1:30 p.m. in front of the Stamford Government Center at 888 Washington Boulevard to demonstrate how proposed gas tax hikes and tolls would hurt small businesses

Others say tolls are inevitable and necessary to shore up the state’s Special Transportation Fund and improve congested roads. If new revenue is not obtained, the STF, which is funded primarily by the gas tax, is projected to post a $338 million deficit by 2022.

The fund for years has been receiving less revenue as cars became more fuel efficient. The state cannot sell bonds for major transportation projects if the STF is insolvent or inadequately funded.

A ballot question in November will ask voters to place a “lock box” on the STF to prevent money from being diverted to uses other than transportation projects.

James Cameron, founder of the Connecticut Commuter Group and a Hearst Connecticut Media columnist, predicted tolls are coming.

“Proposed tolls and taxes seem an inevitable solution to the STF funding crisis,” Cameron said. “The Legislature created this problem, so they can and should solve it.”

Cameron conceded tolls are unpopular.

“None of the options will be popular, especially in an election year, but if they are honest with constituents they’ll explain the necessity,” Cameron noted, referring to legislators.

“The $6 toll from New York to New Haven sounds reasonable, especially compared to the equivalent $8.25 one-way fare on Metro-North at peak,” Cameron added. “Motorists need to pay their fair share, and they haven’t been.”

Gildea added “A strong transportation system is critical to the economy of the state and it’s certainly no coincidence that we have lost Connecticut based businesses to those states that have such a transportation system.”