Scarlett's brontosaurus breasts

Scarlett Johansson nearly crashed her car after being distracted by her giant breasts on a Hollywood billboard.

The sexy star slammed on her brakes when she noticed how her chest had been digitally enhanced on the poster for new movie 'The Island'.

The 20-year-old confessed: "It was the biggest photo of me I had ever seen.

"I screamed and slammed on the brakes. I couldn't believe it. It's very strange to see my cleavage the size of a brontosaurus. My breasts were huge.

"I had long hair and my goodness, I couldn't get past the cleavage."

Although 'The Island', co-starring Ewan McGregor has flopped at the box office, the poster has been a big hit in Los Angeles.

Cars have reportedly been slowing down so fans can get a better look at the sexy star.

Scarlett added of the film: "I got paid to make out with Ewan McGregor and roll around in bed all day. It's a hard job but somebody has to do it!"

(c) BANG Media International