Gungahlin was a strongly Liberal area in the 2012 election but on Saturday that picture was turned on its head, delivering a resounding vote for Labor.

In Franklin, 57 per cent of people who cast their vote in the suburb supported Labor, its biggest result anywhere. Just 27 per cent voted Liberal.

Labor also won more than 46 per cent and as much as 52 per cent at booths in Harrison, Gungahlin centre, Forde, Ngunnawal, Palmerston, Bonner, and Amaroo.

At 2012, the Gungahlin booths were a Liberal stronghold, when the party took more than 50 per cent of the vote in Forde and Nicholls, and polled in the mid 40s in a number of other booths.

Gungahlin Community Council president Peter Elford said while he was surprised at the size of the swing against the Liberals, congestion was the top issue.

A 2014 survey by the council showed 76 per cent of residents strongly supported light rail. Gungahlin residents struggled every day with the commute to work, he said, and probably had an eye to a boost to property values from the tram.

"I think it's pretty reasonable to assume that any anti-light-rail campaign was going to be difficult in Yerrabi," he said. "If I'm a resident of Gungahlin it's kind of all upside."

Labor's Meegan Fitzharris had also built a high profile and campaigned strongly.

Labor-leaning Independent candidate for Yerrabi David Pollard said on the campaign "it all boiled down to light rail – everybody wanted to know what a vote for me meant for light rail".

"Every single person leaving Gungahlin in the morning experiences the congestion, so if we can get any of those people onto light rail, or those roads duplicated, everybody's going to benefit," he said.

Residents didn't share the concerns of other parts of Canberra about urban infill, and the rates hikes were not as big an issue as elsewhere.

The two Gungahlin booths that showed a lesser move to Labor were Nicholls and Hall. In Nicholls, Labor's vote was up from 31 per cent to 36 per cent. But the Liberals still won the day, polling 46 per cent (down from 52 per cent in 2012). In Hall, the vote was steady, on 29 per cent for Labor and 41 per cent for Liberal.

At the 2011 census, Gungahlin showed itself slightly younger than than Canberra average, at a median age of 31 (Canberra 34, Australia 37), more likely to be married, less likely to be university educated, and with a higher Asian population, especially from China and India. Median incomes in Gungahlin are higher than elsewhere in Canberra, and people are more likely to be in full-time work.

Ms Fitzharris said roads and light rail were a big issue in Gungahlin, but it went beyond that.

"I think what most came through was yes, it was about light rail, but it was also about what light rail represented about Canberra's future. They understood that light rail was part of a bigger vision for the city, a prosperous, successful city."

Gungahlin residents embraced growth and with the significant multicultural community were often quite used to medium-density housing.

"They really believe that Canberra can be a hugely liveable city, but have all the opportunities of a larger city, they see growth, they love it. One thing that they don't love is congestion."

Alistair Coe headed the Liberals' campaign in the seat, but was focused on Liberal policy formation and didn't spend as much time on the ground. By far Mr Coe's strongest showing was in the former Belconnen booths, which he represented at the last election. Ms Fitzharris polled poorly in those seats, performing most strongly in the Gungahlin booths.