A public meeting on plans for a downtown relief subway line drew scores of concerned and curious Toronto residents on Saturday.

"The people that I've spoken to so far are just saying, please get on with it, and that's exactly what we're doing," Mayor John Tory told reporters.

The meeting at St James Cathedral Centre, 65 Church St., featured detailed maps of the route of the proposed Relief Line South, a 7.5 kilometre rapid transit line.

The relief line would run from Osgoode Station, across Queen Street and Eastern Avenue, and then north under Pape Avenue, to connect with Pape station on Danforth Avenue, linking Line 1 with Line 2 through eight stations.

Toronto Mayor John Tory listens to a question from a reporter at a meeting on the Relief Line South. (CBC) According to the city, the goal is to have the relief line in place by 2031, with the aim of providing relief for TTC commuters. Saturday's meeting was one of three such public consultations.

Residents expressed concerns about possible noise, vibration and disruption that construction of a subway tunnel could generate.

Tory said a "relatively small" number of properties would be expropriated for the relief line, but the city is not expected to break ground on the project for at least two years.

"That is part of thing that people find, I know, frustrating, is there is so much planning and design," Tory said.

"These are big decisions that could cost hundreds of millions of dollars if you build or not, so we have to listen, we have to refine the project, and planning and design takes years because it's a lot of engineering work."

James Perttula, the city's director of transit and transportation planning, said council has approved the "alignment" for the Relief Line South and the city has just recently launched the formal environment assessment process for the project. (CBC) James Perttula, the city's director of transit and transportation planning, said council has approved the "alignment" for the Relief Line South and the city has launched the formal environment assessment process for the project.

"We are wanting people to be aware that this is coming. As we get through more design, we may need to purchase some properties to make the subway happen," he said.

"We're talking to people about the changes in technology that TTC is using in building subways now that reduce a lot of noise and vibration. It's not like what you feel when you're going down the Bloor-Danforth line anymore. It's much smoother," he said.

City staff were on hand to talk about the project's potential impacts. Some property owners already have received letters from the city about how the project could affect them.

At the meeting, Tory sought to reassure residents.

The meeting featured detailed maps of the route of Relief Line South. (CBC) "There's a lot of sound-proofing technology, and things like that, that would make it much less disruptive than it might be in previous times," Tory said.

Peter Urban, a resident, said he received a letter from the TTC saying the city plans to dig a subway underneath his property. He and his family lives on top of his business.

His concerns include "noise, the timeline, whether we have to close the store or not, how it's going disrupt our life in an everyday manner."

But Urban said he is pleased that the city plans to bore into the ground, as opposed to digging up the road, as it is doing to build the Eglinton Crosstown.

"It enlightened me on some things on how they are going to proceed with the construction and I'm actually quite happy with it," he said.

'We need to have more transit'

TTC riders stand on a crowded subway platform along Line 1. (Tariq Fancy/Twitter) Angela Stone, another resident, said she is concerned about how long the project could take, but was pleased to hear about sound-proofing technology.

Stone said she hope the relief line will eventually alleviate some car traffic. "We need to have more transit," she said.

The city hopes to have a report for council at the end of 2019, with a "much better" design and budget estimate. The project has yet to receive final approval from council.

Tory said the project presents challenges because it would be built in already developed areas.

"Building a subway in a developed city is a bigger task than building one say in a green field area. We are obviously trying to move this ahead as quickly as we possibly can. This is a top priority project and that is why this meeting is happening on a Saturday to get the input we need."

Relief Line North, another project, would extend public transit north from the planned Relief Line South. It would run north from Pape station to connect to either existing or future rapid transit, such as Line 4 Sheppard and Line 5 Eglinton.