Boston Mayor Martin J. Walsh called for a comprehensive plan to overhaul an aging MBTA system and says a push for a temporary tax or fee would be necessary to pay for improvements in the wake of a chaotic scene yesterday at Back Bay Station where a malfunctioning engine filled Orange Line trains with smoke.

“If you want to upgrade the system and have a world class system here in Boston, here in Massachusetts, which we deserve, we need the revenue for it,” Walsh told reporters today in South Boston. “So I think we have to get a little creative here, maybe do some kind of tax with an end in sight.”

Walsh suggested a “10 or 15 year master plan” to upgrade MBTA infrastructure and a tax or fee that would end when the plan is done. The mayor specifically mentioned the sales tax and the gas tax as possible revenue sources.

“You need a steady flow of money coming into the T, and the way you do that is by assessing a fee to something or some type of tax increase and there is certainly a way,” he said. “I think if the public knew the tax increase would be over a 10 year period, but the public knew they'd have a first class transit system, I think the public would be open to the idea.”

Train cars filled with smoke during yesterday’s evening rush hour, forcing panicked patrons to push through windows in order to escape. Walsh said there has to be more MBTA personnel in the stations in case of a situation like the one that occurred yesterday evening.

“There has to be some emergency procedures put in place. Let’s assume it was a fire in the station. Let’s assume the whole train is on fire. There has to be security in place,” Walsh said, noting during his time in the legislature the T said it was going to put ambassadors on trains, something the mayor said he is not seeing. “You have employees on the track to be able to take responsibility and take ownership of what has happened. If people don't know what’s happening, chaos and fear happens. I know it’s a financial thing, but safety trumps financial.”

Walsh imagined what might have happened if his elderly mother had been inside one of those train cars.

“It’s scary, it’s scary, I’d be scared, if I was on the train with my mother. My mother certainly isn't going to be able to climb through a window,” Walsh said. “We have had this conversation for yeas, this is something long before Gov. Baker has come into office.

“This has been going on for how long,” he added. “And we are still having the same conversation. Let’s have a plan and let’s pay for it.”

The mayor said more privatization, something the Baker administration is beginning to implement, is not the answer. He also downplayed the impact of pumping more private dollars into the system through advertising, something suggested this morning on Herald Radio by City Council President Michelle Wu.

“I know they are looking at every bit of advertising dollars and putting advertising all over the place, but you're talking about a plan tha'ts going to take up to billions of dollars to do,” the mayor said. “You need revenue for that. You’re not going to get the majority of that through reorganizing and shuffling privatization, you're not going to get that through advertising.”

Wu took to social media last night, tweeting and retweeting numerous complaints about slow service and delays caused by the Orange Line incident. Walsh said he is criticized every single day on Twitter about the MBTA.

“We have an obligation as leaders to work with the state and the federal government too … long term plans, long term fixes for this,” he said.

A long term plan for transit in Boston was part of the plans for the 2024 Olympic Games in Boston, which Walsh initially supported before saying the city would not guarantee public funds for any cost overruns associated with the games. The USOC withdrew its support for Boston shortly thereafter and backed Los Angeles, which is one of the finalists in the host bidding, the winner of which will be announced next September in Peru. Walsh said having an Olympic-induced deadline to upgrade public transit would have helped.

“We are seeing in L.A., L.A. has the Olympics coming and they are doing major upgrades, they are actually building a tunnel system right now for traffic, now they have a date they have to have it completed by because of the Olympics,” Walsh said. “The people of Boston, Massachusetts deserve better. They shouldn’t have to wait for an Olympics to come.”