A helmet cam has captured the heart-stopping moment a cyclist was almost sideswiped by a TNT Express semi-trailer at the Barton Highway turn-off on Northbourne Avenue.

The footage, recorded by Canberra cyclist Andres Munoz on Monday, comes just over a month after a trial began of new laws mandating motorists maintain a minimum one-metre buffer zone when overtaking cyclists.

Mr Munoz was shaken by the encounter, which he described as "too close for comfort".

"It's a very narrow bike lane but because I'm going to Gungahlin it's the bike lane I'm taking," he said.

"Out of nothing came the truck, he cuts right in front of me. The truck was way behind, he [had] plenty of time to see me. If I didn't brake he would have hit me. He has no idea how quickly I'm going, I'm doing about 35 kilometres per hour."

While it was his first run-in with a truck, Mr Munoz said he's had a few close calls with SUVs, especially on Northbourne Avenue.

"I can't say that every day I have a close encounter but once a week I have one. I've pretty much got video of all of them but this is the first one that really, really freaked me out given the size of the truck."

A heat map of Canberra's cyclist crashes shows Northbourne Avenue is a hotspot for clashes with motorists.

But Mr Munoz believes the trial of the Metre Matters rule, which began its two-year trial in November, has made a difference to people's attitude's to cyclists on the roads.

"People are definitely more aware. You can see in the video all of the people overtaking me prior to the truck give me plenty of room. The truck is the only one where there's a really close shave. It was definitely less than a metre."

The video emerged days after the capital's worst cycling routes were named and shamed by the city's leading cyclist advocacy group.

Barry Drive, between Clunies Ross Street to Northbourne Avenue, topped the list.

Mr Munoz returned to the saddle on Tuesday but concedes he'll probably take a different route next time.

A spokeswoman for TNT Express refused to say whether drivers who travel across state and territory lines are kept abreast of changes in local road rules.

"TNT is investigating the matter and will take appropriate action where necessary," she said.

"TNT Australia is an advocate of safety for all road users and expects its drivers to act carefully, safely and in a professional manner at all times."

An ACT Policing spokeswoman said one person has been issued with a traffic infringement notice for overtaking a bicycle rider too closely since the new laws came into effect.

She said the truck driver could be prosecuted in this scenario however a statement from Mr Munoz would be required.