The ACT government has decided to keep minimum distances for motorists passing cyclists after a report found they may have reduced the number of crashes.

Following a rule change letting cyclists ride over pedestrian crossings, the study also found an increase in collisions with motorists, prompting calls for warning signage and education campaigns.

Road Safety Minister Shane Rattenbury will on Thursday announce the territory will adopt the road rules permanently despite the report failing to conclude they had increased safety.

The rules require motorists to stay one metre clear of cyclists when overtaking them in speed zones of 60km/h or less, and 1.5m in speed zones greater than 60km/h.

Road rules were also changed to let motorists cross, straddle or drive on centre-lines and painted islands when overtaking cyclists, provided it was safe to pass them.

While a lack of data stopped the study from saying conclusively the rules had increased safety, it said there were fewer crashes during the test period starting in 2015, and that awareness and support for minimum passing distances had grown.

The report showed the number of reported bicycle-related crashes reduced slightly from 401 to 386 between the pre-trial and trial periods. Minimum passing distance-related crashes also decreased from 20 to 18.

Mr Rattenbury is expected to admit there is further work needed to collect evidence about cycling safety, but will draw attention to the study's finding that attitudes towards cycling improved during the trial.

“These reforms are designed to encourage more cycling and keep cyclists safe. It’s clear that the safer cycling reforms have made a positive difference in our community, and that more Canberrans are both aware of, and support, them," he said.

“We’ll continue to make it easier, safer and more convenient for people to choose cycling as their preferred method of transport."

The study, by the University of Adelaide's Centre for Automotive Safety Research, found the number of cyclists in Canberra fell during the trial period but those reporting cycling more frequently increased.

It also echoed calls from cycling groups for greater education about the new rules, and reinforced previous figures released under freedom of information laws showing police were issuing few infringement notices.

Police issued 11 infringement notices during the trial, in some cases only after reports from cyclists, prompting the study to call for investigations into ways to improve enforcement.

There was no evidence the minimum passing distance rules created greater risk of collisions for motorists, but crashes between motorists and cyclists riding across pedestrian crossings increased from 22 to 35 during the trial.

"This may confirm initial concerns from some ACT residents that cyclists may suddenly ride across pedestrian crossings from footpaths without giving enough time for motorists to react," the report said, calling for further investigation.

The report recommended an education campaign telling motorists and cyclists to slow down when nearing pedestrian crossings, and urged the government to widen crossings, and install speed platforms and warning signage.

The study also found a small decrease in the number of collisions between cyclists and motor vehicles on pedestrian crossings where there were no shared paths.

More than 90 per cent of people responding to surveys were at least "somewhat supportive" of a minimum overtaking distance for motorists passing cyclists. Nearly 70 per cent were at least 'somewhat supportive' of cyclists being allowed to slowly ride across pedestrian crossings, rather than having to stop and dismount to cross, an increase compared to before the trial.