Ottawa mayoral candidate Clive Doucet ​says it's "unfair" to expect him to detail how he'll pay for one of his key — and potentially costliest — campaign promises.

In an interview with CBC Radio's Ottawa Morning on Monday, Doucet was asked what he'd cut in order to pay for his idea of returning to weekly garbage pickup in the summer months.

"I can't tell you where we're going to pull out one particular item, as you need to have a budget process. And I think it's a little unfair, asking me to do that kind of division at this point," he said.

Doucet defended the idea against criticism from some, including Ecology Ottawa's Robb Barnes, that it's "a step backwards."

"What I heard at the doorstep and parks, the first thing I heard from people was in the summertime, because of the heat ... people really wanted to have a weekly pickup. I heard it over and over again," Doucet said.

"Part of listening to people is not just listening to what you want to hear, but what they're saying to you.... So I thought, let's give it a whirl."

To keep waste down, Doucet said the city should be spending more to educate people on how to make more use of their green bins.

Regional rail

Doucet has promised to create a regional rail system linking communities including Fitzroy Harbour, Kinburn, Kanata, Stittsville, Smiths Falls, Barrhaven, Orlé​ans and Limoges to downtown Ottawa.

On social media in early September, Doucet showed a rail network stretching as far into western Quebec as Chelsea, Que., and boulevard Lorrain in eastern Gatineau, Que.

Asked Monday how he planned to get so many governments on board, Doucet appeared to backtrack, saying the rail line will stop only at Place du Portage, just across the Ottawa River.

Doucet said he'd cancel the city's Baseline busway project, which will cost about $10 million per kilometre, to pay for his regional rail idea, which he said would cost about $3 million per kilometre.

"You want to build a four-tier system. You want better community service, better commuter service, LRT of course, and then good regional rail, just like Toronto," Doucet said.

On incumbent mayor Jim Watson's debt:

"When you're doubling your debt in eight years, that's worrisome.... As mayor, I would not want to be doubling the debt every eight years and reducing services. He's got less affordable housing today than he did eight years ago, transit ridership is down.... It doesn't inspire me. I'm seeing bigger costs and lower services right across the board."

On changing the location of the new Civic hospital from Tunney's Pasture to the Central Experimental Farm:

"I want to know why that was changed from Tunney's Pasture. I don't think [people] probably do [want that file reopened] but still I would like to know why it got changed.... Why did a bunch of politicians get together and virtually in 72 hours, with no reason given, make the change? I would like to know why."

On transparency:

"One of the problems with this government is it's very secretive.... We don't know about what's going on in the tunnel and [the Confederation Line]. It's a mystery to most people. [Rideau Transit Group] cannot talk to us directly. Why the constant delays? Think about it; we have councillors appealing to commissioners of privacy for information on the tunnel, the city's own councillors against the mayor.

"I'd open the books, I'd unlock City Hall, I would not be afraid of talking to the public. I would actually listen to what people say and then move on what they say."