BOSTON - Anticipating a decade of traffic delays during the reconstruction of a key portion of the Massachusetts Turnpike, a new report proposes the Worcester commuter rail line be converted to electrified, frequent, subway-like service to ease traffic jams and prove the concept of regional rail.

“The need for frequent and reliable transit and rail mobility along this corridor is urgent,” said the report, “Regional Rail Proof of Concept: How Modern Operating Practice Adds Capacity to the Current Commuter Rail Network,” by transportation advocacy nonprofit TransitMatters. “The MBTA should immediately increase off-peak frequency, and invest money in electrification and new rolling stock to commence high-quality Regional Rail operations as soon as possible.”

The nonprofit group estimates the cost of the Worcester line at $500 million. It proposes paying for this - and the conversion to a full regional rail system - by reallocating money from the $2 billion to $3 billion proposed expansion of South Station.

“With better operations, the South Station expansion is unnecessary and its budget can be reinvested in better projects, such as high-level platforms and electrification across the entire MBTA regional rail system,” the report states. “The resources exist; they simply need to be spent wisely.”

The report, released Thursday, follows TransitMatters’ February 2018 report proposing regional rail as the future of commuter rail. The report defines regional rail as “a vision of fast, frequent, all-day electrified trains service for the Boston metropolitan region.”

The most recent report is divided into two sections and expands on the regional rail proposal.

The first section focuses on how modernizing operations - such as regular scheduling, and quicker turn times at South Station accomplished through minor track upgrades and dedicated tracks - can add capacity to the commuter rail system and increase train frequency.

But perhaps most importantly, this involves the electrification of the system. In addition to being more reliable, electric locomotives can accelerate and decelerate faster than diesel locomotives and - in combination with modern, single-level coaches with multiple doors to enable quicker boarding and unloading - shave time off the trip.

“The bottom line: with the high reliability of electric trains ... and mostly separated tracks between lines, it is possible to run trains with high schedule discipline,” the report states. “High schedule discipline in turn permits running trains more regularly and more often.”

Indeed, the report envisions eight trains per hour (four in each direction) on the Worcester line during peak hours.

The second half of the report expands on this vision for the Worcester line by proposing it as a “proof of concept” for regional rail.

It is the perfect time, according to the report.

The $1.2 billion reconstruction of the Pike in Allston, as well as private development of air rights in the area, are predicted to cause traffic delays over the course of a decade beginning in 2022. In addition, the Worcester line is in demand: It saw 46 percent ridership growth from 2012 to 2016 and, with 18,637 average weekday riders in 2018, it is the Massachusetts Bay Transportation Authority’s second busiest.

To mitigate the impact of the construction, the report proposes immediate changes that Jarred Johnson, chief operating officer of TransitMatters, called a “regional rail lite.”

The report proposes service every 15 minutes during rush hour and at least hourly off-peak. This would require (in addition to several items mentioned in the first section of the report) additional labor and fuel costs, moving the layover area closer to the Mass. Pike/Route 128 intersection to activate trains that idle during the day in Allston, and a commitment to keep two tracks on the Worcester line in operation throughout the duration of the Allston project.

This could be done within two years, Mr. Johnson estimated in an interview, at a cost of around $1 million annually. But it would need to begin immediately.

In the mid-term, priorities include high-level, full-length platforms at each station (some are in the plans already, such as the center platform at Union Station) and track and signal upgrades to allow speeds up to 100 mph compared with the current maximum speed of 60 mph.

Mr. Johnson estimated this would take two to five years at roughly $300 million in costs, estimating about $10 million to $15 million for each station that needs to be upgraded.

The final step - achievement of full regional rail - would come with electrification of the line, hopefully within five to seven years, according to Mr. Johnson. He estimated this would cost about $100 million for the Worcester line. TransmitMatters plans to issue reports on the cost of electrification for each line in the future.

Mr. Johnson acknowledged that this might be a high cost to some, but emphasized that it would eliminate the need to expand South Station. Also, when coupled with other recommendations in the report - for instance, the proposed North-South Rail Link, lowering fares on the Worcester line to increase ridership, and the construction of the new West Station early during the Allston Multimodal Project - it could transform not just a decade of construction delays but the commuter rail.

“There may be some folks that get sticker shock when they see the costs - but we feel there’s a significant cost to not having a well-thought-out transit plan during a decade of construction,” Mr. Johnson said. “There are lots of projects on the wish list, but here’s a report that can save $2 to $3 billion and here’s a practical step we can do ... to get better service very soon.”