A survey of small businesses has found more than 80 per cent believe congestion in Sydney has got worse in the last year.

Motoring organisation NRMA surveyed 382 businesses that are members of its roadside assistance service.

It found that more than a third of respondents have changed their business habits as a result of congestion.

75 per cent said their journey to work was longer that a year ago, while 42 per cent have incurred costs as high as $10,000 because of congestion.

NRMA President Wendy Machin says business owners are frustrated with the New South Wales Government for not doing more to fix the problem.

She says some businesses have been forced to move outside the CBD.

"That's a real indictment on a major city like Sydney to think that we're forcing people out of the place where they want to do business because the traffic is simply too bad for them to do business there," she said.

The New South Wales Business Chamber's Paul Ritchie says incentives are needed so people travel at different times.

"According to the RTA, 20 per cent of peak travel is related to parents taking their children to school," he said.

"So how can we create some incentives in terms of different starting times for schools?"

The New South Wales Transport Minister David Campbell says the number of vehicles on some Sydney's roads has risen, but travel times have not increased significantly.

"Traffic on Sydney's major roads has increased by 46 per cent over the past 18 years but travel times on Sydney's most important roads has remained steady," he said.

"[That's] through a mix of large infrastructure projects and smaller initiatives, such as the pinch point program, and improving public transport."