A significant increase in Boston’s population over the next fifteen years will put an inexorable burden on Boston’s suffocated roadways and inadequate public transport systems, necessitating a new transportation plan founded on “credibility and trust,” Rick Dimino, chief executive of A Better City, told Boston Public Radio on Wednesday.

Dimino and Barry Bluestone, co-author of the State of the Built Environment Report, professor at Northeastern University, and founding director of the Kitty and Michael Dukakis Center for Urban and Regional Policy, explained that “as many as 80,000 more vehicles” may clog up our roadways in 15 years, according to a recent calculation by Northeastern University.

With cars already crawling at 10 miles per hour around the city, where will more vehicles go?

Bluestone warned that the additional “243 miles of cars and trucks” would bring traffic to a standstill, but the data is “not all discouraging.” There’s ample opportunity for change: people need to find ways to live closer to work and utilize the commuter rail, and likely more people will live in urban centers rather than suburbs in coming years. In terms of air travel, the increase in passenger travel attributed to Boston’s climb to “global city” status will require bigger planes with higher occupancies and may compel cities like Providence or Manchester to bear some of Logan’s load.

However, the report illuminates the cracks in existing public transportation infrastructure, deepened by the recent development of what Dimino called “growth areas” such as the South Boston Waterfront. Red Line trains are consistently delayed and some workers are even resorting to Razor Scooters to get around the Seaport.

Dimino added that the Mayor is “very aspirational...and also very focused on how he can partner with the governor to make mass transit a better solution.” With the silver line oversaturated to 128% capacity at peak hours, “experimental silver line vehicles” are a possible solution. Factoring in the potential stress of those 80,000 drivers on public transport, Bluestone suggested that trains double their frequency by running every 3 minutes.

While there is a pressing need for significant capital investment, the source of funding is uncertain. Dimino warned, “we can’t piecemeal our way out of this transportation finance problem.” From the Millionaire’s Tax to a value-capture model, which Bluestone cite as potential funding sources, there are various approaches to kicking a new transportation system into gear.

To hear more from Rick Dimino and Barry Bluestone, click on the audio link above.