Children in separated families continue to spend more time with their mothers despite law reforms aimed at promoting shared parenting.

The Australian Institute of Family Studies tracked more than 10,000 separated parents who split following the Howard government's 2006 family law reforms
The changes were designed to encourage 50-50 parenting arrangements, while increasing services to help parents reach custody agreements out of court.

But since the reforms, shared parenting arrangements have increased only slightly and at a similar rate to that post reforms.

The study shows about 16 per cent of children have a shared care arrangement, most commonly a 35/65 split in favour of their mothers.

But 80 per cent continue to spend most nights with their mother, and eleven per cent don't see their father at all.

While mothers continue to be the primary carers, the number of custody cases ending up in court has dropped by 22 per cent since the reform.

The majority of people involved in the family law system, including judges and parents, believe the changes have been an improvement on the old system.

Lawyers, however, remain divided, arguing that the changes have been complex and favour fathers in relation to property settlements and child support payments.

They are also concerned fathers expect equal custody arrangements, regardless of the interests of the child.

University of Sydney family law expert Patrick Parkinson agrees that the notion of equal time can give a false sense of entitlement to parents.

"It's only one of many options that can work, depending on the circumstances," he told AAP, noting in many cases sole custody arrangements are needed.

"It may actually prevent judges from making the hard calls they ought to."

Professor Parkinson points out that Australia is lagging behind other developed countries when it comes to shared parenting arrangements.

But he says the barriers are not legal, but social and economic.

"A lot of people try shared care but it doesn't last longer than a year," he said, explaining parents often need to find cheaper accommodation away from their children.

Labor has proposed amendments to the Family Law Act, which Professor Parkinson says will only make a difference "at the very margins".

The draft laws incorporate a UN convention on children's rights, which would compel the court to consider protecting a child above custody rights.