A task force appointed by Montgomery County Executive Isiah Leggett recommends creating special taxing districts to fund express bus lanes along Colesville Road, Georgia Avenue and the Intercounty Connector, according to a highly anticipated report released Tuesday.

The report is the most comprehensive study for designing a 160-mile network of express bus lanes aimed at easing traffic in one of the region’s most congested areas. The system is estimated to cost about $1.8 billion to build and $180 million a year to maintain.

But coming up with the funding could prove difficult — and unpopular. The special taxing districts could significantly increase property taxes.

One type of district would tax residents and business owners living within half a mile of the routes. The other would tax 90 percent of county properties — virtually everything but farms in rural areas.

Depending on the plan, the average household could see its bill rise, at the peak point, as little as $320 and as much as $580. For the average business, it could be as little as $425 and as much as $2,175.

The task force is also pushing to create dedicated lanes for the express buses, which could mean taking lanes from automobiles in some dense neighborhoods.

At a news conference Tuesday, Leggett (D) said he would amend the county’s budget to include money to begin work on the system within a few months.

“We cannot delay implementation of this initiative,” he said earlier in a statement.

Leggett, the Montgomery County Council and Gov. Martin O’Malley (D) recently endorsed the buses, which are called “Rapid-Transit Vehicles,” over a light rail system, which officials concluded was too costly and would take too long to build.

The bus system would have up to 25 routes, including the Corridor Cities Transitway, that span major state roads and county thoroughfares. Most would be along Interstate 270 and in the more densely populated southern part of the county. The buses would run every four minutes, according to the report, and connect to the county’s Ride On bus system. By 2040, it would account for up to 207,000 trips a day.

More than 80 percent of the routes would require new construction, according to the report. It remains unclear whether dedicated bus lanes — which are important to ensure speedy transportation — can be built for all routes along the system. Creating space for such lanes may become too expensive, task force members said.

Despite the cost — and the additional burden on taxpayers — the report says the county desperately needs more public transportation. “The investment and sacrifice will be worthwhile — and our community will look back with pride,” the report says.

In weighing methods to pay for the project, the task force considered other sources of revenue, such as increases in the income and sales taxes. But it concluded that the alternatives could not be relied on to generate enough revenue and that such uncertainty could endanger the county’s AAA bond rating.

The group looked at different financing options based on the special taxing districts, most of which would require the state legislature’s approval. But in every scenario, property taxes would increase, peak in the near future and then drop or level off, the report says.

A property tax could be a tough sell, especially to pay for buses, which are perceived by some advocates as an inferior alternative to rail.

In its report, the task force offers a less-expensive alternative: a smaller version of the system, with more than 80 miles of bus lanes across seven routes. The smaller system would cost about $1.2 billion to build and $90 million a year to maintain.

This month, O’Malley said he would seek a special federal grant to help pay for the CCT, which would connect the Red Line and northwest Montgomery. But the task force says in its report that financing the rest of the system using this grant would be “mishandl[ing]” the funds.

Thomas J. Street, an assistant chief administrative officer for the county, said Leggett will release his budget amendment within a month.

County staff members are working on how much it would allocate toward the project, but Street said the money would go to fine-tuning the special taxing districts, negotiating right-of-way agreements with the state and completing preliminary analyses on several of the bus routes.

In the report, the task force assumes that bus fares will cost $1 and that some bus routes would start in 2016.