PORTLAND — Independent gubernatorial candidate Eliot Cutler announced on Tuesday that, if elected, he’ll make smoothing out potholes and eliminating cellphone dead zones among his top priorities.

Cutler highlighted his proposals to tackle perhaps two of Maine’s most irritating problems, especially in rural parts of the state, during a Tuesday announcement of his 21-point plan to invest heavily in transportation and communication infrastructure.

The news conference was the latest in a series of high-profile announcements by the three major gubernatorial candidates as each attempts to grab momentum in the contentious race with bold signature initiatives or proposals.

Last month, Republican incumbent Gov. Paul LePage held an event in Brunswick to trumpet his newly proposed “Open for Business Zones,” which would create “right-to-work” areas where employees could opt out of paying fees for being represented by unions in collective bargaining. He also has been hammering away at addressing abuse of Maine’s welfare system, another prominent campaign theme.

The Democratic candidate, U.S. Rep. Mike Michaud, D-Maine, unveiled an economic development plan in February seeking to raise the state’s minimum wage from $7.50 to $9 and waive tuition for sophomores in the University of Maine System.

Representatives of both the LePage and Michaud campaigns on Tuesday afternoon said their candidates have shown similar commitments to rebuilding Maine’s roads and communications infrastructure.

In his latest salvo Tuesday, Cutler stopped short of putting a price tag on his transportation and communication plan, but acknowledged the cost would be significant. To help pay for road repairs, he said the state could consider a new mileage fee for vehicles, among other measures.

While Cutler said such a fee was only one of a variety of revenue generating options, if Maine were to implement such a tax, it would be following in the footsteps of Oregon, which last year launched a system to charge 5,000 volunteer drivers 1.5 cents per mile traveled as a replacement for what had been regular gas tax payments.

“Maine is operating 20th century transportation and communication infrastructure that simply isn’t adequate to support a robust 21st century economy,” Cutler said during a news conference in a Portland park overlooking the city’s International Marine Terminal.

The independent said he would work with cellphone service providers to identify dead zones and eliminate them, and would promote a so-called “dig once” policy to piggyback fiber-optic high-speed Internet lines along with other underground infrastructure projects, such as natural gas line expansions.

Cutler said Maine currently has the second slowest Internet speeds in the U.S., and spotty cellphone coverage in the state’s rural areas not only limits business connectivity in those places, but also threatens to deter out-of-state tourists who rely on their mobile phones.

“We can’t allow any part of Maine to continue to be a dead cell zone,” he said.

To help fund better road maintenance, Cutler said he would push Maine’s congressional delegation to help the state get a greater share of its gas taxes back from the Federal Highway Trust Fund.

Currently, the independent said Maine only gets $2.72 per foot of state-administered highway in fuel tax revenue from the federal fund, the lowest amount in New England. Nearby New Hampshire receives $7.04 per foot for highway upkeep from the fund, while Massachusetts gets $10.50 back per foot.

The lower revenues come as the numbers of Maine vehicles, drivers and miles traveled has increased, Cutler said. There were more than 1.5 million registered vehicles in Maine in 2009, compared with about 500,000 in 1970, the candidate said, yet with increased fuel efficiencies, gas tax revenues to help maintain the roads have not kept up with the additional wear and tear.

He also said the Maine Department of Transportation’s budget for highway and bridge maintenance is underfunded by between $110 million and $150 million each year, and pledged to “close that gap” if elected.

Cutler said there are several ways to boost revenues to better keep up with the road work, including dipping into the state’s general fund, more or higher tolls, higher gas taxes, bonds or the aforementioned new charge per mile traveled.

The latter would represent a significant change for Mainers, who already pay among the highest gas taxes in the country and bristled at recent increases in the tolls charged by the Maine Turnpike Authority.

“The amounts we will borrow and invest will be substantial,” Cutler acknowledged, but said the moves would “generate revenue far in excess of what we put in.”

The independent cited Federal Highway Administration estimates that every $100 million spent on highway construction supports about 2,780 jobs, and said Mainers on average spend nearly $245 each for annual car repairs because of potholes and poorly maintained roads.

Using those numbers, Cutler said heavy investments in smoothing out the roads would save Maine residents about $230 million statewide in pocket money. He equated the roadwork proposal to a de facto tax cut on Maine drivers.

“I’ve never seen it like this,” said Cutler of the seasonal frost heaves and potholes. “It’s not just a bad winter — it’s the price we’re paying for years and years of neglect.”

In response, Lizzy Reinholt, spokeswoman for the Michaud campaign, noted that the economic development plan unveiled by the congressman in February included a 10-year pledge to authorize at least $100 million in annual bond money for transportation and telecommunications infrastructure projects.

“In his ‘Maine Made’ plan, Congressman Michaud has proposed a 10-year investment strategy that will strengthen our roads and bridges, rail lines and ports, while also expanding access to high-speed Internet,” Reinholt said in a statement. “His plan will bring predictability and stability to state investments, create jobs and help the economy to grow.

“Perhaps more importantly, Congressman Michaud is the only person in the race with a proven track record of bringing people together to find common-sense solutions to problems facing Maine, including finding the resources for needed investments, and he’s the best person to beat Gov. LePage this fall,” she continued, in part.

Brent Littlefield, a strategic adviser for the LePage campaign, said on Tuesday afternoon the “liberal politician Cutler is very long on words and very short on substance.”

Littlefield noted that LePage assembled a task force to study broadband development, and credited the governor with lobbying mobile phone carriers to invest more than $70 million in infrastructure over the past two years.

“[I]n just his first year in office, Gov. LePage’s Department of Transportation completed more projects — road improvements and infrastructure fixes — than Gov. [John] Baldacci did previously while spending $100 million less,” Littlefield said in a statement.

LePage has already announced a new $2 billion road and infrastructure plan for this year, Littlefield noted.