The $331million bypass project was completed in April last year, allowing 20 intersections and many traffic signals to be avoided along the old Western Highway route.

But many residents are questioning what the advantage has been, with traffic being held up for up to half an hour at peak times each day due to there being only a single lane, Christies Road, leading from Caroline Springs to the bypass.

Caroline Springs Residents Association president Joy Cox said her members expressed frustration every month and had contacted VicRoads several times with no luck.

"This is very frustrating," she said. "We have been talking to VicRoads and they have been saying there's nothing they can do about it.

"Every month we complain about the same thing to them.

"Coming out of Caroline Springs into Christies Road, you turn down one lane, and the same goes for coming into Caroline Springs from the bypass. The traffic builds up and it can take you anything from half an hour to an hour just to get across Ballarat Road and into Caroline Springs."

Council planning and development general manager Luke Shannon said the council was aware of significant traffic backlogs on Christies Road, but it was part of the network managed by VicRoads.

"Accordingly, council has raised the issue with VicRoads and they are reviewing the options available to address the situation."

But according to VicRoads, Christies Road is a local

road for which the shire is responsible.

Cambridge Ward's Cr Garry Stock said he believed VicRoads needed to do a count of cars travelling down Christies Road. "Up to a kilometre of cars are blocked during peak hour and cars are now backed to Station Road in Deer Park to the Western Highway because Christies Road is taking so much time.

"The answer is to provide two lanes into Christies Road from Caroline Springs."

Nam Nguyen, 30, who moved to Caroline Springs from StAlbans two years ago, said he found it hard to believe that infrastructure in Caroline Springs would be overlooked, considering the area's constant population growth. "The rest of Caroline Springs is OK."

"It's just that something as important as the road onto the bypass should have been thought out better.

"I am surprised they have built a single-lane entrance onto the bypass. I thought that at the very least there would be a double lane each way; it's a bit disappointing to see we're stuck with one."