Almost 99 per cent of Victoria's taxi drivers have been stumped by the industry's new knowledge test, which was introduced just six months ago.

The Taxi Services Commission said 444 prospective and existing drivers took the test between July and December, but only six people have passed all three modules required for accreditation.

Taxi Services Commissioner Graeme Samuel described the results as "very poor".

"The industry had 18 months of warning about this test and they don't seem to be responding," Mr Samuel said.

"You've just got to wonder what's going through the mind of the industry, whether they're just simply being either recalcitrant or lazy, or just simply not recognising that the attitude of the Taxi Services Commission is we will have better drivers on the road."

The test must be completed by all new drivers in metropolitan Melbourne, and those with less than five years' experience, with drivers allowed two attempts to pass each assessment within a 12-month period.

It includes three modules testing general and geographical knowledge, as well as driver behaviour and customer service.

Each module requires applicants to answer 55 questions in an hour.

They must also meet a "satisfactory degree" of understanding and proficiency in the English language.

Very tricky test, taxi driver says

13Cabs driver trainer Karen Downey has worked in the industry for 35 years and was the first person to pass the test.

"It's very tricky," Ms Downey said.

The taxi 'knowledge test': Introduced July 1, 2014

Introduced July 1, 2014 444 people have sat the test

444 people have sat the test 6 people have passed all three modules

6 people have passed all three modules 54 people have passed one or more modules

54 people have passed one or more modules 17 existing drivers have failed a module twice, losing their endorsement

"Sometimes you have to read the question two or three times to work out what it is they want to know, and then there's multiple correct answers for the same question."

She said the test questions should be made clearer, and drivers should be given better feedback on their results.

"I think people who are not successful need to be given their score, because currently you just get passed or 'not yet competent'," she said.

The Taxi Services Commission said 17 existing drivers have failed a module twice, which meant they would lose their endorsement to drive a metropolitan Melbourne taxi.

Taxi Industry Association said it was supportive of the concept of the knowledge test, but was very concerned at poor success rate.

"What we'd really like for Graeme Samuel to do is work with the industry to resolve the problems, we don't need to have a blame game I don't think," spokeswoman Georgia Halliday said.

"We're really keen to have good drivers out there on the road, but we need to have an appropriate way to assess them, and I don't think we're there right now."

The Taxi Services Commission said it would release a new study guide for drivers within months in an effort to address the low pass rate.