'It's a bit short," he admitted. "If I want to stretch out I've got to move the pillow up a little bit and put my legs down to the end and put them around between the seat and the pillar of the car. When I get out in the morning I'm doubled over because I've been in that cramped position all night."

John has been sleeping this way for more than four years, despite recurring bouts of pneumonia and Canberra nights so cold icicles form on the inside of his windscreen.

He is one of the people who frequents Safe Shelter, which opens its doors three nights a week from April to September for up to eight men to sleep.

He finds the hall at St Columba's too cold to drift off in, but John still pops along each night for several hours to enjoy a hot drink and the company of the other men and volunteers who seek respite under its roof, before retiring to his car.

But while it's a temporary reprieve from the boredom and loneliness homelessness brings, John said the limited number of nights the shelter opens means it is underutilised by Canberra's permanent homeless population.

"If they give up their spots they might not get it back so it's not worth them coming here for three nights," he said.

He said he's received calls from Canberrans urgently seeking emergency accommodation as late as 12.30pm but has had nowhere to direct them as Safe Shelter was closed.

"I don't begrudge these people calling me or waking me up but the only trouble is I've got to say 'no, I don't know where you can go'," he said.

The number of guests seeking out Safe Shelter is on track to exceed those of previous years, Mr Griffiths said.

But apart from their crude numbers, it's hard to determine scale of homelessness in Canberra due to insufficient data.

That's about to change, according to OneLink manager Julie Evans.

OneLink, which is a partnership between Woden Community Service, Belconnen Community Service and the ACT Government, replaced former homelessness service portal FirstPoint as well as the Child, Youth and Family Gateway on July 1.

The new service, which retains the old Firstpoint phone number, aims to collate more data on the demand on homelessnesss services here in Canberra, as well as provide a one-call portal for human services in the ACT.

Already, OneLink has extended its hours of operation and Ms Evans said it's about determining: "where is the demand, where is the need."

Kate Crawford, director of Children, Youth and Family at Woden Community Service, said the service will "evolve based on demand".

"We've only been operating for four weeks now and we're receiving an average of 44 calls per day form services and from the community," she said.

Another Safe Shelter sleeper, Barry, 53, came to Canberra more than a month ago because he believed there were less homeless people here.

With the exception of a few, fleeting periods, Barry has been unable to find suitable long-term accommodation for almost a decade and currently lives in backpacker hostels for two weeks at a time.

He said once you start floating from place to place, it can be difficult to tether yourself again.

"It doesn't take very long before your rental history is eroded. I was living in Cairns for a while where I had an apartment but I had to leave, there was a lot of violence and drugs in the area I was at and I didn't feel safe, but once I left that and I was two or three months down the track, my rental history was out the door. It's very hard to get back into the mainstream [after that]," he said.

The slope becomes even more slippery when you throw jobseeking into the mix, he said.

"Even when you go for a job now they want to know where you live, how long you've lived there for, it's on the application. It's the same thing when you go for accommodation, they want to know where you work and how long you've worked there for. Normally one goes to the other. That's not an excuse but I can't see myself coming out of a backpackers' place or sleeping rough and going to work."

You can call OneLink on 1800 176 468 from 8am-6pm Monday to Friday. Safe Shelter will be open from 7pm every Tuesday, Wednesday and thursday night until September at St Columba's Church in Braddon.