And she said it's an experience she's put up with in the capital for the past 10 years, branding Canberra the worst city in Australia for those with a disability.

Social sciences Associate Professor Helen Meekosha, of the University of NSW, was left stranded twice by the ACT's wheelchair accessible taxi service, which left her waiting in sub-zero temperatures at Canberra Airport on Monday night.

Forced to wait more than an hour for a suitable taxi that never arrived, she finally gave up and decided to have her wheelchair dismantled and loaded into a regular taxi.

The next day the multiple sclerosis sufferer said she was so tired from the arduous journey that she abandoned her roundtable meeting with Attorney-General Nicola Roxon, the reason for her visit to Canberra.

But the ordeal did not end there.

Professor Meekosha missed her 9.15am flight to Sydney on Wednesday after her booked wheelchair taxi arrived at 8.45am - 45 minutes late.

Professor Meekosha has been visiting Canberra for disability roundtables with the Attorney-General as a voluntary advocate for the past decade.

She said the 36 hours of hell was not uncommon in the capital.

''This is a just a normal part of going to Canberra, it's always a disaster … [Canberra's] so behind the times,'' Professor Meekosha said. ''The world is getting better, but unfortunately I feel that it's embarrassing to have a capital city where the service feels like a village, that doesn't seem to be in this century in terms of disability access.''

Professor Meekosha said the experience was humiliating.

''The disrespect gets me, feeling like you're nobody of consequence while everyone else files into ordinary taxis,'' she said. ''You're made to feel like you're asking for something completely out of the ordinary.''

But a Justice and Community Safety spokeswoman said such incidents were not common, despite a shortage of wheelchair taxis on ACT roads.

ACT government figures show almost one-third of the capital's 26 wheelchair accessible taxi licences are unused, leaving only 18 on the road.

The government received 13 official complaints about long wait times and the inability of the network to accommodate a wheelchair booking in the 2011-12 financial year.

The spokeswoman said there were also several phone calls received reporting long wait times. She said there were limited wheelchair taxis on the road on week nights.

''It is advisable for [wheelchair accessible taxi] users to pre-book their transport with the taxi networks to ensure an appropriate vehicle is available at the required time,'' the spokeswoman said.

''Accredited taxi networks provide monthly summary sheets on performance against waiting time standards [and] the data provided by the taxi networks indicates that the waiting time performance for [wheelchair accessible taxis] is the same as waiting times for standard taxis.''

But the government apologised to Associate Professor Meekosha for her substandard treatment.

Canberra Taxi Industry Association executive director Tony Bryce said the shortage of wheelchair taxis and drivers could be a major factor in Professor Meekosha's tale of woe.