The latest Report on Government Services also suggests the ACT Supreme Court's proportion of criminal cases waiting two years or longer remainsthe worst in the country, although there are promising signs that recent efforts to curb delays are having real success.

On Friday the Productivity Commission released the justice component of its comprehensive report on the performance of Australian governments.

It showed that prisoners at the Alexander Maconochie Centre, spent 8.9 hours a day on average out of their cell in 2013-14 - the second lowest of any jurisdiction in Australia.

The ACT is lagging well behind the Northern Territory, which gave prisoners 13 hours a day on average out of their cells - the highest of any state or territory.

Canberra's prison was promised as a human rights-compliant facility.

But the Human Rights Commission has previously warned that excessive lockdowns are a potential violation of the territory's Human Rights Act, which guarantees humane treatment for those deprived of their liberty.

The ACT was also the third worst performer in the country for employing prisoners while in custody.

The report found that only 69.5 per cent of AMC inmates eligible for work were actually being employed.

The ACT's prison did shine in educating prisoners, with by far the highest number of eligible prisoners in courses during 2013-14.

The prison also had the country's highest rate of serious assaults by one prisoner on another, although that fell from the previous year and is likely to be skewed due to a small inmate population.

Less serious assaults between prisoners rose from the previous year to 5.43 per 100 prisoners in 2013-14.

Corrections Minister Shane Rattenbury said he was pleased with the improved recidivism figures, and the relatively low overall number of prison assaults showed a strong and positive staff culture.

"ACT Corrective Services continues to demonstrate its ability to manage the significant increase in detainee numbers, in addition to progressing a number of major projects including new facilities," Mr Rattenbury said.

The report revealed mixed results with the long-running issue of delays in the ACT Supreme Court.

The backlog indicator for the percentage of non-appeal Supreme Court criminal cases that have dragged on for more than 24 months continued to be the poorest nationally in 2013-14, although it has improved on previous years.

The percentage of cases waiting 12 months or longer, however, improved signifcantly, was closer to the national average, and markedly better than Tasmania, NSW, and South Australia.

The Supreme Court also appears to be cutting through the pending criminal caseload, the commission's report reveals.

It recorded the highest clearance rate of cases - the number finalised divided by the number lodged - in the country, at 106.6 per cent in 2013-14.

That high clearance rate and decreasing backlog coincided with the appointment of Chief Justice Helen Murrell in October last year, who vowed to cut court delays from the outset.

Attorney-General Simon Corbell welcomed the figures and said they showed a 56 per cent reduction in criminal matters and a 59 per cent decrease in civil matters since 2009-10.

He said pending cases in the Coroner's Court had also reduced by 47 per cent.

"Since 2009 the ACT justice system has undergone a series of changes and these figures show that the reforms are continuing to produce successful results."

The report also reflected an improvement in Canberrans' perceptions of safety, a problematic area that has been out of touch with the ACT's relatively low crime rates in the past.

Canberrans felt the safest in the country in using public transport at night and the second safest walking alone in their neighbourhood at night.

There was also a high overall satisfaction with policing services and high regard for police integrity.