Robbie Williams WA concert organisers respond to frustrated fans ...

Furious fans were left stuck in hours-long traffic jams last night as they made their way to and from Robbie Williams' concert in Western Australia's Swan Valley.

About 15,000 people ventured to Nikola Estate to see the British pop star perform.

Organisers have apologised and recommended concert-goers arrive early to the singer's second show tonight.

"Regarding the traffic issues experienced at last night's Robbie Williams concert, we share your disappointment and frustration," Mellen Events said in a statement.

"We sincerely apologise for the inconvenience this caused.

"We acknowledge the traffic delays that people experienced were extremely inconvenient."

Event organisers worked with Main Roads today to add an additional entrance to the venue and establish a different bus route.

"Significant changes have been made in an effort to improve our patron's experience getting to and from the venue for tonight's show," the organisers said.